Supersymmetry Transformations for Delta Potentials
We make a detailed study of the first and second-order SUSY partners of a one-dimensional free Hamiltonian with a singular perturbation proportional to a Dirac delta function. It is shown that the second-order transformations increase the spectral manipulation possibilities offered by the standard f...
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| citation_txt | Supersymmetry Transformations for Delta Potentials / David J. Fernández C., M. Gadella, L.M. Nieto // Symmetry, Integrability and Geometry: Methods and Applications. — 2011. — Т. 7. — Бібліогр.: 66 назв. — англ. |
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| description | We make a detailed study of the first and second-order SUSY partners of a one-dimensional free Hamiltonian with a singular perturbation proportional to a Dirac delta function. It is shown that the second-order transformations increase the spectral manipulation possibilities offered by the standard first-order supersymmetric quantum mechanics.
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Symmetry, Integrability and Geometry: Methods and Applications SIGMA 7 (2011), 029, 14 pages
Supersymmetry Transformations for Delta Potentials?
David J. FERNÁNDEZ C. †, Manuel GADELLA ‡ and Luis Miguel NIETO ‡
† Departamento de F́ısica, Cinvestav, AP 14-740, 07000 México DF, Mexico
E-mail: david@fis.cinvestav.mx
‡ Departamento de F́ısica Teórica, Atómica y Optica, Facultad de Ciencias,
47041 Valladolid, Spain
E-mail: manuelgadella1@gmail.com, luismi@metodos.fam.cie.uva.es
Received November 30, 2010, in final form March 19, 2011; Published online March 22, 2011
doi:10.3842/SIGMA.2011.029
Abstract. We make a detailed study of the first and second-order SUSY partners of a one-
dimensional free Hamiltonian with a singular perturbation proportional to a Dirac delta
function. It is shown that the second-order transformations increase the spectral manipula-
tion possibilities offered by the standard first-order supersymmetric quantum mechanics.
Key words: first and second-order SUSY; singular potentials
2010 Mathematics Subject Classification: 81Q60
1 Introduction
The study of one-dimensional Hamiltonians with a point interaction has received renewed atten-
tion during the past two decades [1, 2, 3, 4, 5, 6, 7]. In general, a point interaction is described
by a potential concentrated either in a single or a discrete number of points as it happens, e.g.,
for the Dirac delta or its derivative. Mathematically, in order to define these potentials, we use
the theory of extensions of symmetric operators with equal deficiency indices. These extensions
have domains which are characterized by some matching conditions for the wave functions at
the points supporting the interaction [2, 8, 9, 10, 11]. In particular, the Dirac delta barrier or
well have been extensively studied in this way with or without other interactions [12], with or
without mass discontinuities at the singular points etc. [13, 14].
On the other hand, supersymmetric quantum mechanics (SUSY QM) has emerged as the
standard technique for generating new potentials with known spectra departing from an initial
one [15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
39, 40, 41]. The method has been applied successfully to regular one-dimensional potentials
defined on the full real line [42, 43], on the positive semi-axis [44, 45] or in a finite interval [46].
Although there are some works dealing with SUSY QM applied to point potentials [47, 48, 49,
50, 51, 52, 53], however the corresponding study has been done just for particular first-order
SUSY transformations, without analyzing the full possibilities of spectral manipulation offered
by the method. It is interesting to note as well that a point potential may appear as hidden
supersymmetries [54, 55].
Now, it is the appropriate time for studying the behavior of point potentials with bound
states under SUSY QM. Due to the calculation complexity, we shall focus our attention to first
and second-order transformations, which anyway are interesting by themselves [56, 57, 58, 59].
?This paper is a contribution to the Proceedings of the Workshop “Supersymmetric Quantum Me-
chanics and Spectral Design” (July 18–30, 2010, Benasque, Spain). The full collection is available at
http://www.emis.de/journals/SIGMA/SUSYQM2010.html
mailto:david@fis.cinvestav.mx
mailto:manuelgadella1@gmail.com
mailto:luismi@metodos.fam.cie.uva.es
http://dx.doi.org/10.3842/SIGMA.2011.029
http://www.emis.de/journals/SIGMA/SUSYQM2010.html
2 D.J. Fernández C., M. Gadella and L.M. Nieto
We shall restrict the discussion to the following one-dimensional Hamiltonian
H0 = −1
2
d2
dx2
+ V0(x), V0(x) := −aδ(x), a > 0, (1)
which is mathematically well defined and self-adjoint provided that we use as its domain D the
subspace of the Sobolev space W 2
2 (R/{0}) such that for any ψ(x) ∈ D, one has: ψ(0+)
ψ′(0+)
=
1 0
−2a 1
ψ(0−)
ψ′(0−)
, (2)
where ψ(0+), ψ′(0+) and ψ(0−), ψ′(0−) are the right and left limits of ψ(x), ψ′(x) at the origin
respectively [2].
In order to achieve our goal, we have organized this paper as follows: in Section 2, we will
study the solutions of the stationary Schrödinger equation for the Hamiltonian H0 given by (1).
In Section 3 we will apply the first-order SUSY techniques, in Section 4 we will analyse the
second-order transformations and in Section 5 we will present our conclusions.
2 Solution of the Schrödinger equation
Let us evaluate in the first place the general solution of the stationary Schrödinger equation for
an arbitrary ε = −k2/2 < 0:
H0u(x) = εu(x), (3)
with H0 given in (1). There is one solution vanishing for x→ −∞, denoted u+(x), of the form
u+(x) = ekxH(−x) + (α ekx + βe−kx)H(x), k > 0, (4)
where H(x) is the Heaviside step function, and α, β are constants to be determined from the
discontinuity equations (2). We need as well the derivative of u+(x),
u′+(x) = ku+(x)− 2kβe−kxH(x) + (α+ β − 1)δ(x). (5)
From equations (4) and (5) it turns out that
u+(0+) = α+ β, u+(0−) = 1, u′+(0+) = k(α− β), u′+(0−) = k. (6)
On the other hand, using equations (2) and (6), we obtain:
α+ β = 1, α− β = 1− 2ã,
where ã = a/k. Hence:
α = 1− ã, β = ã.
Inserting these expressions in equations (4) and (5), we finally get
u+(x) = ekx − ã
(
ekx − e−kx
)
H(x), (7)
u′+(x) = ku+(x)− 2ae−kxH(x).
Note that the Hamiltonian H0 in equation (1) is invariant under the change x→ −x. Thus,
we can find a second linearly independent solution u−(x) for the same ε = −k2/2, vanishing
now for x→∞, by applying this transformation to u+(x):
u−(x) = ã
(
ekx − e−kx
)
H(−x) + e−kx. (8)
Supersymmetry Transformations for Delta Potentials 3
Moreover:
u′−(x) = −ku−(x) + 2aekxH(−x).
Finally, the general solution of equation (3) for ε = −k2/2 < 0 is a linear combination of both (7)
and (8) which, up to an unessential constant factor, becomes:
u(x) = u+(x) +Du−(x) = ekx +De−kx − ã
(
ekx − e−kx
)
[H(x)−DH(−x)] , (9)
where D is a constant. The corresponding derivative is given by:
u′(x) = −ku(x) + 2kekx [1− ãH(x) +DãH(−x)] . (10)
Note that, up to normalization, both solutions u±(x) lead to the same bound state for k0 = a:
ψ0(x) =
√
a
[
ek0xH(−x) + e−k0xH(x)
]
.
The corresponding eigenvalue becomes
E0 = −a
2
2
,
which coincides with the result derived in [11].
On the other hand, the scattering states for ε = κ2/2 > 0 can be simply obtained from
the solutions given in equations (7), (8) by the substitution k → −iκ, κ > 0. In particular,
for a probability flux approaching the singularity from −∞ the corresponding scattering state
arises in this way from the u−(x) of equation (8), which (up to unessential constant factor) leads
to
ψ(x) =
[
eiκx +
ia
κ− ia
e−iκx
]
H(−x) +
κ
κ− ia
eiκxH(x). (11)
It is clear now that the reflection R and transmition T coefficients become the standard ones
(see, e.g., [60]):
R =
∣∣∣∣ ia
κ− ia
∣∣∣∣2 =
a2
κ2 + a2
, T =
∣∣∣∣ κ
κ− ia
∣∣∣∣2 =
κ2
κ2 + a2
. (12)
3 First-order SUSY transformations
Let us start with the initial Schrödinger Hamiltonian H0 given in (1). As it is well known (see,
e.g., [37, 41] and the references cited there), its first-order SUSY partner,
H1 = −1
2
d2
dx2
+ V1(x),
is intertwined with H0 in the way
H1A
+
1 = A+
1 H0, (13)
where
A+
1 =
1√
2
(
− d
dx
+
u′
u
)
.
4 D.J. Fernández C., M. Gadella and L.M. Nieto
Here, the transformation function u(x) is the seed solution given in (9), associated to the fac-
torization energy ε = −k2/2 and satisfying equation (3). The SUSY partner potential V1(x) of
V0(x) is given by:
V1(x) = V0(x)− [lnu(x)]′′. (14)
We assume the standard restriction ε ≤ E0 ⇒ k ≥ k0, in order to avoid the creation of new
singularities in V1(x) with respect to those of V0(x). Note that, from equation (14) and (3) we
have:
V1(x) = V0(x)− u′′(x)
u(x)
+
[
u′(x)
u(x)
]2
= −V0(x) + 2ε+
[
u′(x)
u(x)
]2
. (15)
Hence, a straightforward calculation using equations (9), (10) leads to:[
u′(x)
u(x)
]2
= k2 − 4k2(1− ã)
u2(x)
[
D + ãD2H(−x) + ãH(x)
]
. (16)
As ε = −k2/2, equations (15), (16) give:
V1(x) = aδ(x)− 4k2(1− ã)[D + ãD2H(−x) + ãH(x)]
{ekx +De−kx + 2ã sinh(kx)[DH(−x)−H(x)]}2
. (17)
Note that the denominator of equation (17) never vanishes for x ∈ (−∞,∞) and D ≥ 0.
Moreover, it can be seen that the delta term in V1(x) is now repulsive (since a > 0).
A straightforward consequence of the intertwining relationship (13) is that for any eigenfunc-
tion ψ of H0 associated to the eigenvalue E (H0ψ = Eψ) such that A+
1 ψ 6= 0, it turns out that
ψ(1) ∝ A+
1 ψ ∝ W (u, ψ)/u is a corresponding eigenfunction of H1 associated to E. Moreover,
if ψ satisfies as well equation (2) it turns out that ψ(1) now obeys:(
ψ(1)(0+)
ψ(1)′(0+)
)
=
(
1 0
2a 1
)(
ψ(1)(0−)
ψ(1)′(0−)
)
,
which is consistent with the fact that the intensity of the delta term in V1(x) has an opposite
sign compared with V0(x) and the second term of V1(x) has just a finite discontinuity at x = 0
(see equation (17)).
Concerning the spectrum of H1, let us note in the first place that A+
1 transforms the scattering
eigenfunctions of H0 into the corresponding ones of H1. In particular, the wavefunction ψ(x)
given in equation (11), when transformed by acting on it with A+
1 , produces an expression
ψ(1)(x) which is a bit large to be presented here. However, for large values of |x| that expression
reduces to the following scattering one (up to a constant factor):
ψ(1)(x) →
|x|→∞
[
eiκx +
(
a
a+ iκ
)(
−k + iκ
k + iκ
)
e−iκx
]
H(−x)
+
(
iκ
a+ iκ
)(
−k + iκ
k + iκ
)
eiκxH(x).
This means that the initial reflection and transmission coefficients are unchanged under the
first-order SUSY transformation (compare equation (12)). We thus conclude that the continuous
spectrum of H0 belongs as well to the spectrum of H1.
Let us note that the differences in the spectra ofH1 andH0 rely in general in the modifications
produced by a non-singular SUSY transformation on the discrete part of the initial spectrum. For
first-order transformations, these changes can be classified according to the essentially different
combinations of the parametersD ≥ 0 and k ≥ k0 which characterize the seed eigenfunction u(x).
We can find three different situations.
Supersymmetry Transformations for Delta Potentials 5
(i) Creation of a new ground state at ε < E0. This case appears for D > 0, k > k0. Here, the
eigenfunction ψ
(1)
ε ∝ 1/u(x) of H1 associated to ε is square-integrable. Moreover, since the
mapped initial ground state ψ
(1)
0 = 1√
2
1√
E0−ε
W (u,ψ0)
u is as well a normalized eigenfunction
of H1 with eigenvalue E0, then Sp(H1) = {ε, E0} ∪ [0,∞) = {ε} ∪ Sp(H0).
(ii) Isospectral transformations. These are achieved from the previous case either by taking
D → 0 or D → ∞. Since in both situations u(x) goes to zero at one of the ends of the
x-domain, it turns out that ψ
(1)
ε ∝ 1/u(x) is no longer square-integrable, although ψ
(1)
0 is.
Thus, Sp(H1) = {E0} ∪ [0,∞) = Sp(H0).
(iii) Deleting E0. This situation arises from the previous one by taking k=k0 =a (ã=a/k=1).
Since u(x) ∝ ψ0(x) is square-integrable, then ψ
(1)
ε ∝ 1/u(x) is not normalizable, and then
Sp(H1) = [0,∞). From equation (17), it is clear that now
V1(x) = aδ(x). (18)
This means that, by deleting the bound state of the attractive delta well V0(x) = −aδ(x),
a > 0, which is placed at E0 = −a2/2, we recover the repulsive delta barrier of equa-
tion (18), a standard result well known in the literature.
4 Second-order SUSY transformations
In this section it will be illustrated, by means of the delta-well potential, the advantages for
manipulating spectra of the second-order SUSY transformations [56, 57, 58, 59] compared with
the first-order ones. It is nowadays known that the second-order SUSY partners H2 of the initial
Hamiltonian H0 can be generated either by employing two eigenfunctions u1(x), u2(x) of H0,
not necessarily physical, associated to two different factorization energies ε1,2, ε1 6= ε2 [37, 41]
or by an appropriate eigenfunction u1(x) in the limit when ε2 → ε1 (the so called confluent
case [61, 62]). In both situations the two Hamiltonians H0, H2 are intertwined by a second-
order operator in the way
H2B
+
2 = B+
2 H0,
where
B+
2 =
1
2
(
− d
dx
+
u
(1)
2
′
u
(1)
2
)(
− d
dx
+
u′1
u1
)
, u
(1)
2 =
w(x)
u1(x)
,
the new Hamiltonian H2 takes the standard Schrödinger form
H2 = −1
2
d2
dx2
+ V2(x),
and the second-order SUSY partner V2(x) of the initial potential V0(x) is given by
V2(x) = V0(x)− [lnw(x)]′′, (19)
the real function w(x) being proportional in general to the Wronskian of two generalized eigen-
functions of H0 [63]. An explicit classification of the several second-order SUSY transformations
is next given.
6 D.J. Fernández C., M. Gadella and L.M. Nieto
4.1 Confluent case [61, 62]
Let us consider in the first place the limit ε2 → ε1 ≡ ε = −k2/2 < 0, taking as seed the
Schrödinger solution u+(x) vanishing as x 7−→ −∞, which means to take the u(x) given in
equation (9) with D = 0, namely:
u(x) = ekx − 2ã sinh(kx)H(x). (20)
In this case the real function w(x) appearing in equation (19) takes the form [62]
w(x) := w0 +
∫ x
−∞
u2(y) dy.
An explicit calculation for x ≤ 0 leads to:∫ x
−∞
u2(y) dy =
∫ x
−∞
e2ky dy =
e2kx
2k
.
On the other hand, for x > 0 it turns out that:∫ x
−∞
u2(y) dy =
∫ 0
−∞
u2(y) dy +
∫ x
0
u2(y) dy
=
ã
k
+
(1− 2ã)
2k
e2kx +
ã2
k
sinh(2kx) + 2ã(1− ã)x.
By combining these two results, we obtain
w(x) = w0 +
e2kx
2k
+
[
ã
k
− ã
k
e2kx +
ã2
k
sinh(2kx) + 2ã(1− ã)x
]
H(x). (21)
The second-order SUSY partner potential of V0(x) becomes now
V2(x) = −aδ(x) +
u4(x)
w2(x)
− 2u(x)u′(x)
w(x)
. (22)
Note that, since u′(0+) = k − 2a and u′(0−) = k, then u′(x) and consequently the potential
difference ∆V (x) = V2(x)− V0(x) have a finite discontinuity at x = 0.
In order to avoid the arising of extra singularities for V2(x) with respect to V0(x) we have
to take w0 ≥ 0. Concerning the spectrum of H2, a similar calculation as in the first-order case
shows that the scattering eigenfunctions of H0 are mapped into the corresponding ones of H2,
i.e., the energy interval [0,∞) belongs to Sp(H2). As for the discrete part of the spectrum,
several possibilities of spectral manipulation emerge, according to how we choose k and w0.
(i) Creating a new bound state at ε 6= E0. This case appears by taking w0 > 0 and k 6= k0 = a.
Since
lim
|x|→∞
ψ(2)
ε ∝ lim
|x|→∞
u(x)
w(x)
∝ e−k|x|,
the eigenfunction ψ
(2)
ε of H2 associated to ε is square-integrable, i.e., a new bound state
has been created at ε, either below the ground state for k > k0 or above it for k < k0.
The last option is illustrated in Fig. 1, where we have plotted the potential difference
∆V (x) as a function of x for a = 2, k = 1, w0 = 1, i.e., a new level was created at
ε = −1/2 > E0 = −2 (see the two gray horizontal lines in the same graph). Note the
existence of a finite discontinuity in ∆V (x) at x = 0, induced by a similar discontinuity
of u′(x) at the same point.
Supersymmetry Transformations for Delta Potentials 7
-2 2 4
-3
3
Figure 1. Potential difference ∆V (x) as function of x (blue lines) induced by the confluent second order
SUSY transformation for a = 2, k = 1, w0 = 1. A new level was created at ε = −1/2, above the initial
ground state E0 = −2 (gray horizontal lines).
(ii) Isospectral transformations. They arise in the first place as a limit of the previous case
for ε 6= E0 and w0 → 0. Note that the long explicit expression for the V2(x) of (22) which
would appear if we would substitute explicitly the u(x) and w(x) of equations (20), (21)
becomes strongly simplified in this limit:
V2(x) = −aδ(x) +H(x)
(
8ãk2e2kx[(ã− 1)e2kx − ã]{(ã− 1)[2kx(ã− 1) + 1− 2ã]e2kx
+ ã[2kx(ã− 1) + 2ã− 3]}
)/{
(ã− 1)2e4kx+ 2ã[1− 2kx(ã− 1)]e2kx− ã2
}2
.
Since now
lim
x→−∞
u(x)
w(x)
=∞,
it turns out that ε 6∈ Sp(H2) = {E0} ∪ [0,∞) = Sp(H0).
An alternative way to produce isospectral transformations is to use the single bound state
of H0 for evaluating w(x). The corresponding formula is achieved from equation (21) by
taking k = k0 = a, ã = 1, which leads to:
w(x) = w0 +
e2ax
2a
− 2
a
sinh2(ax)H(x) . (23)
Hence
V2(x) = −aδ(x)− 8w0a
3e2ax
(2w0a+ e2ax)2
H(−x) +
8a2e2ax(1 + w0a)
[2(1 + w0a)e2ax − 1]2
H(x). (24)
Note that now w(x) does not have any node for
w0 ∈
(
−∞,−1
a
)
∪ (0,∞) .
Moreover, in this domain it turns out that
lim
|x|→∞
u(x)
w(x)
∝ e−a|x|,
i.e., ψ
(2)
ε ∝ u(x)/w(x) is square-integrable ⇒ Sp(H2) = {E0} ∪ [0,∞) = Sp(H0).
8 D.J. Fernández C., M. Gadella and L.M. Nieto
(iii) Deleting the ground state of H0. By taking now the limit of equation (23) for w0 → 0 or
w0 → −1/a, it turns out that lim
x→−∞
u(x)/w(x) =∞ or lim
x→∞
u(x)/w(x) =∞ respectively.
In both cases ψ
(2)
ε is not square-integrable and then
E0 6∈ Sp(H2) = [0,∞).
This result means that we have deleted the ground state of H0 in order to obtain H2. For
w0 → 0 the potential of equation (24) becomes
V2(x) = −aδ(x) +
8a2e2ax
(2e2ax − 1)2
H(x). (25)
On the other hand, for w0 → −1/a the corresponding potential V2(x) is obtained from the
previous one by the change x→ −x.
Let us remark that, although the final spectra of the SUSY partner Hamiltonians of H0
are the same when deleting its ground state in the first-order and in the confluent second-
order transformations, however the potentials V1(x) and V2(x) are physically different (compare
equations (18) and (25)). In particular, note the opposite signs of the coefficients of the Dirac
delta function for both potentials.
4.2 Complex case [64, 65, 66]
Let us assume that k = kR + ikI is complex with kR > 0, kI ∈ R, and suppose that the two
involved factorization energies are now given by ε = −k2/2 and ε̄, where z̄ denotes the complex
conjugate of z. Since we need to avoid the arising of extra singularities in the new potential, we
will take a Schrödinger seed solution vanishing at one of the ends of the x-domain in the form
given in equation (20) with k ∈ C, namely,
u(x) = ekx − 2a
k
sinh(kx)H(x), ū(x) = ek̄x − 2a
k̄
sinh(k̄x)H(x). (26)
To compute now the second-order SUSY partner potential V2(x), we have to obtain in the first
place the Wronskian W (u, ū) and then the real function
w(x) =
W (u, ū)
2(ε− ε̄)
.
This calculation is cumbersome but otherwise straightforward, which leads to:
w(x) =
e2kRx
2kR
+
{
− a
|k|2
[
cosh(2kRx)− cos(2kIx)
]
+
a(a− kR)
|k|2kRkI
[
kI sinh(2kRx)− kR sin(2kIx)
]}
H(x). (27)
Then, V2(x) will be given by
V2(x) = −aδ(x) +
|u(x)|4
w2(x)
− [u(x)ū′(x) + ū(x)u′(x)]
w(x)
, (28)
with u(x), ū(x) and w(x) as given in equations (26) and (27). An illustration of the potential
difference ∆V (x) as function of x for a = 2, k = 1/100 + i/10 is given in Fig. 2.
Supersymmetry Transformations for Delta Potentials 9
-5 5 15
-0.5
-0.3
-0.1
0.1
Figure 2. Potential difference ∆V (x) as function of x induced by the complex second order SUSY
transformation for a = 2, k = 1/100 + i/10. The two potentials V2(x) and V0(x) are isospectral.
Note that these equations become highly simplified if kR = a:
w(x) =
e2ax
2a
−
(
a
a2 + k2
I
)
[cosh(2ax)− cos(2kIx)]H(x), (29)
|u(x)|2 = e2ax −
(
2a
a2 + k2
I
)
[a sinh(2ax) + kI sin(2kIx)]H(x). (30)
Moreover, for the particular choice kR = a we get a more compact expression for the new
potential V2(x) than for a generic kR that would appear if we would substitute the u(x) and w(x)
of equations (26), (27) in equation (28):
V2(x) = −aδ(x) +H(x)
(
4a2e2ax[2(a2 − k2
I ) cos(2kIx)(a2 − k2
Ie
4ax) (31)
− 4akI sin(2kIx)(a2 + k2
Ie
4ax) + 8a2k2
Ie
2ax]
)/[
a2 − k2
Ie
4ax − 2a2e2ax cos(2kIx)
]2
.
Let us remark that, for the general case characterized by equations (26) and (27) as well as
the particular ones described by equations (29)–(31), the scattering states of H0 are mapped
into the corresponding ones of H2, and the same happens for the bound state. Thus, it turns out
that the spectrum of H2 will be equal to Sp(H0) = {E0}∪ [0,∞), i.e., the complex second-order
SUSY transformations which produce a real final potential are strictly isospectral.
4.3 Real case
Let us take now two seed solutions u1, u2 in the form given in equation (9), associated to the
pair of real factorization energies ε2 < ε1 ⇒ k2 > k1. Their explicit forms, and the corresponding
derivatives, are given by:
ui(x) = ekix +Die
−kix + 2ãi sinh(kix)[DiH(−x)−H(x)], (32)
u′i(x) = −kiui(x) + 2kie
kix [1− ãiH(x) +DiãiH(−x)] , i = 1, 2,
where ãi = a/ki. Similarly as in the complex case, the calculation of the Wronskian w(x) ≡
W (u1, u2) of the two involved Schrödinger seed solutions is once again cumbersome, but a con-
venient compact expression reads:
w(x) = (k1 − k2)u1u2 + 2k2u1e
k2x [1− ã2H(x) +D2ã2H(−x)]
10 D.J. Fernández C., M. Gadella and L.M. Nieto
-4 -2 2 4
-2
-1
1
Figure 3. Potential difference ∆V (x) as function of x (blue lines), induced by a real second order SUSY
transformation for a = 2, k2 = 1, k1 = 1/2, D1 = −1/2, D2 = 1. Note that two new levels were created
above E0 = −2, at the positions ε2 = −1/2 and ε1 = −1/8 (gray horizontal lines).
− 2k1u2e
k1x [1− ã1H(x) +D1ã1H(−x)] .
By employing this equation, it is straightforward to calculate the new potential through:
V2(x) = −aδ(x) +
(
w′
w
)2
− w′′
w
= −aδ(x) +
[
(k2
1 − k2
2)u1u2
w
]2
+
(k2
1 − k2
2)(u1u
′
2 + u′1u2)
w
.
Concerning the spectrum of H2, once again the scattering states of H0 are mapped into the
corresponding ones of H2. As for the discrete part of the spectrum, several possibilities are
worth of study.
(i) Creating two new levels. Let us suppose first that ε1 6= E0 6= ε2. In order that w(x)
do not have nodes, the two factorization energies must be placed either both below (for
k2 > k1 > a) or both above E0 (for k1 < k2 < a). Moreover, according to the chosen
ordering ε2 < ε1, the solution u2(x) must have one extra node with respect to u1(x) [37].
In the domain k2 > k1 > a (ε2 < ε1 < E0) this can be achieved by taking D2 < 0 and
D1 > 0 while for k1 < k2 < a (E0 < ε2 < ε1) it must be taken D2 > 0 and D1 < 0. With
this choice of parameters, it turns out that the two eigenfunctions of H2 associated to ε1
and ε2, ψ
(2)
ε1 ∝ u2/w and ψ
(2)
ε2 ∝ u1/w, are square-integrable. Thus,
Sp(H2) = {ε2, ε1} ∪ Sp(H0),
i.e., two new levels have been created for H2, either both below the ground state of H0 (for
k2 > k1 > a) or both above E0 (for k1 < k2 < a). An illustration of the last situation is
shown in Fig. 3, where we have plotted the potential difference ∆V (x) for a = 2, k2 = 1,
k1 = 1/2, D1 = −1/2, D2 = 1. As a result of the transformation, two new levels were
created above the ground state energy of H0 at the positions ε2 = −1/2 and ε1 = −1/8
(see the gray horizontal lines at Fig. 3).
(ii) Creating one new level. This case arises from the previous one for D2 → 0. Now it turns
out that ψ
(2)
ε2 is not square-integrable anymore, meaning that
Sp(H2) = {ε1} ∪ Sp(H0).
Thus, in order to generate H2 a new level has been created at ε1, above E0 for k1 < a and
below it for k1 > a.
Supersymmetry Transformations for Delta Potentials 11
(iii) Isospectral transformations. These can be achieved from case (i) for D1 = D2 → 0, where
both ψ
(2)
ε1 and ψ
(2)
ε2 cease to be square-integrable so that εi 6∈ Sp(H2), i = 1, 2. Hence,
Sp(H2) = Sp(H0).
(iv) Moving the level E0. This procedure is obtained from case (i), e.g., by taking ε2 = E0,
D2 → 0, u2(x) ∝ ψ0(x), and u1(x) as given in equation (32) with D1 < 0, ε1 > E0.
With this choice it can be shown that ψ
(2)
ε2 ∝ u1/w is not square-integrable but ψ
(2)
ε1 does,
meaning that
Sp(H2) = {ε1} ∪ [0,∞).
In a way, the level E0 has been moved up to ε1 for generating H2.
(v) Deleting the level E0. This can be achieved as a limit of the previous case for D1 → 0.
Now it turns out that lim
x→0
u2/w =∞, i.e., ε1 6∈ Sp(H2), and hence
Sp(H2) = [0,∞).
5 Conclusions
We have employed the first and second-order supersymmetric quantum mechanics for generating
new potentials with modified spectra departing from the delta well potential. The first-order
transformation allowed us to change just the ground state energy level, while the second-order
transformations enlarged the possibilities of spectral control, including the option of manipula-
ting the excited state levels. On the other hand, it is important to remember that the first-order
transformations induced in the new potential a delta term with an opposite sign compared with
the initial one (physically the delta term changed from attractive to repulsive). Meanwhile, the
second-order transformations generated a delta term with exactly the same sign as the initial
one (the attractive nature was preserved under the transformation). These physical differences
should be taken into account in the determination of the most appropriate transformation for
building a potential model. We can conclude that supersymmetric quantum mechanics is a po-
werful mathematical tool, which is quite useful for implementing the spectral design in physics.
Acknowledgement
Partial financial support is acknowledged to the Spanish Junta de Castilla y León (Project
GR224) and the Ministry of Science and Innovation (Projects MTM2009-10751 and FPA2008-
04772-E). DJFC acknowledges the support of Conacyt.
References
[1] Seba P., Some remarks on the δ′-interaction in one dimension, Rep. Math. Phys. 24 (1986), 111–120.
[2] Kurasov P., Distribution theory for discontinuous test functions and differential operators with generalized
coefficients, J. Math. Anal. Appl. 201 (1996), 297–323.
[3] Coutinho F.A.B., Nogami Y., Fernando Perez J., Generalized point interactions in one-dimensional quantum
mechanics, J. Phys. A: Math. Gen. 30 (1997), 3937–3945.
[4] Toyama F.M., Nogami Y., Transmission-reflection problem with a potential of the form of the derivative of
the delta function, J. Phys. A: Math. Theor. 40 (2007), F685–F690.
[5] Fülöp T., Tsutsui I., A free particle on a circle with point interaction, Phys. Lett. A 264 (2000), 366–374,
quant-ph/9910062.
http://dx.doi.org/10.1016/0034-4877(86)90045-5
http://dx.doi.org/10.1006/jmaa.1996.0256
http://dx.doi.org/10.1088/0305-4470/30/11/021
http://dx.doi.org/10.1088/1751-8113/40/29/F05
http://dx.doi.org/10.1016/S0375-9601(99)00850-6
http://arxiv.org/abs/quant-ph/9910062
12 D.J. Fernández C., M. Gadella and L.M. Nieto
[6] Hejcik P., Cheon T., Irregular dynamics in a solvable one-dimensional quantum graph, Phys. Lett. A 356
(2006), 290–293, quant-ph/0512239.
[7] Christiansen P.L., Arnbak H.C., Zolotaryuk A.V., Ermakov V.N., Gaididei Y.B., On the existence of res-
onances in the transmission probability for interactions arising from derivatives of Dirac’s delta function,
J. Phys. A: Math. Gen. 36 (2003), 7589–7600.
[8] Albeverio S., Gesztesy F., Høegh-Krohn R., Holden H., Solvable models in quantum mechanics, Texts and
Monographs in Physics, Springer-Verlag, New York, 1988.
[9] Albeverio S., Kurasov P., Singular perturbations of differential operators. Solvable Schrödinger type opera-
tors, London Mathematical Society Lecture Note Series, Vol. 271, Cambridge University Press, Cambridge,
2000.
[10] Gadella M., Kuru Ş., Negro J., Self-adjoint Hamiltonians with a mass jump: general matching conditions,
Phys. Lett. A 362 (2007), 265–268.
[11] Gadella M., Negro J., Nieto L.M., Bound states and scattering coefficients of the −aδ(x) + bδ′(x) potential,
Phys. Lett. A 373 (2009), 1310–1313.
[12] Fernández C., Palma G., Prado H., Resonances for Hamiltonians with a delta perturbation in one dimension,
J. Phys. A: Math. Gen. 38 (2005), 7509–7518.
[13] Gadella M., Heras F.J.H., Negro J., Nieto L.M., A delta well with a mass jump, J. Phys. A: Math. Theor.
42 (2009), 465207, 11 pages.
[14] Álvarez J.J., Gadella M., Heras F.J.H., Nieto L.M., A one-dimensional model of resonances with a delta
barrier and mass jump, Phys. Lett. A 373 (2009), 4022–4027.
[15] Witten E., Dynamical breaking of supersymmetry, Nuclear Phys. B 185 (1981), 513–554.
[16] Mielnik B., Factorization method and new potentials with the oscillator spectrum, J. Math. Phys. 25 (1984),
3387–3389.
[17] Fernández D.J., New hydrogen-like potentials, Lett. Math. Phys. 8 (1984), 337–343, quant-ph/0006119.
[18] Andrianov A.A., Borisov N.V., Ioffe M.V., Quantum systems with identical energy spectra, JETP Lett. 39
(1984), 93–97.
[19] Andrianov A.A., Borisov N.V., Ioffe M.V., The factorization method and quantum systems with equivalent
energy spectra, Phys. Lett. A 105 (1984), 19–22.
[20] Sukumar C.V., Supersymmetric quantum mechanics of one-dimensional systems, J. Phys. A: Math. Gen.
18 (1985), 2917–2936.
[21] Sukumar C.V., Supersymmetric quantum mechanics and the inverse scattering method, J. Phys. A: Math.
Gen. 18 (1985), 2937–2955.
[22] Sukumar C.V., Supersymmetry, potentials with bound states at arbitrary energies and multi-soliton
configurations, J. Phys. A: Math. Gen. 19 (1986), 2297–2316.
[23] Sukumar C.V., Supersymmetry and potentials with bound states at arbitrary energies. II, J. Phys. A: Math.
Gen. 20 (1987), 2461–2481.
[24] Beckers J., Dehin D., Hussin V., Symmetries and supersymmetries of the quantum harmonic oscillator,
J. Phys. A: Math. Gen. 20 (1987), 1137–1154.
[25] Alves N.A., Drigo Filho E., The factorization method and supersymmetry, J. Phys. A: Math. Gen. 21
(1988), 3215–3225.
[26] Lahiri A., Roy P.K., Bagchi B., Supersymmetry in quantum mechanics, Internat. J. Modern Phys. A 5
(1990), 1383–1456.
[27] Roy B., Roy P., Roychoudhury R., On solutions of quantum eigenvalue problems: a supersymmetric ap-
proach, Fortschr. Phys. 39 (1991), 211–258.
[28] de Lange O.L., Raab R.E., Operator methods in quantum mechanics, The Clarendon Press, Oxford Univer-
sity Press, New York, 1991.
[29] Baye D., Phase-equivalent potentials for arbitrary modifications of the bound spectrum, Phys. Rev. A 48
(1993), 2040–2047.
[30] Sparenberg J.-M., Baye D., Supersymmetric transformations of real potentials on the line, J. Phys. A: Math.
Gen. 28 (1995), 5079–5095.
[31] Bagchi B., Supersymmetry in quantum and classical mechanics, Chapman & Hall/CRC Monographs and
Surveys in Pure and Applied Mathematics, Vol. 116. Chapman & Hall/CRC, Boca Raton, FL, 2001.
http://dx.doi.org/10.1016/j.physleta.2006.03.070
http://arxiv.org/abs/quant-ph/0512239
http://dx.doi.org/10.1088/0305-4470/36/27/311
http://dx.doi.org/10.1016/j.physleta.2006.10.029
http://dx.doi.org/10.1016/j.physleta.2009.02.025
http://dx.doi.org/10.1088/0305-4470/38/34/005
http://dx.doi.org/10.1088/1751-8113/42/46/465207
http://dx.doi.org/10.1016/j.physleta.2009.09.002
http://dx.doi.org/10.1016/0550-3213(81)90006-7
http://dx.doi.org/10.1063/1.526108
http://dx.doi.org/10.1007/BF00400506
http://arxiv.org/abs/quant-ph/0006119
http://dx.doi.org/10.1016/0375-9601(84)90553-X
http://dx.doi.org/10.1088/0305-4470/18/15/020
http://stacks.iop.org/0305-4470/18/2937
http://stacks.iop.org/0305-4470/18/2937
http://dx.doi.org/10.1088/0305-4470/19/12/016
http://dx.doi.org/10.1088/0305-4470/20/9/032
http://dx.doi.org/10.1088/0305-4470/20/9/032
http://dx.doi.org/10.1088/0305-4470/20/5/024
http://dx.doi.org/10.1088/0305-4470/21/15/010
http://dx.doi.org/10.1142/S0217751X90000647
http://dx.doi.org/10.1002/prop.2190390304
http://dx.doi.org/10.1103/PhysRevA.48.2040
http://stacks.iop.org/0305-4470/28/5079
http://stacks.iop.org/0305-4470/28/5079
Supersymmetry Transformations for Delta Potentials 13
[32] Cooper F., Khare A., Sukhatme U., Supersymmetry in quantum mechanics, World Scientific Publishing
Co., Inc., River Edge, NJ, 2001.
[33] Mielnik B., Rosas-Ortiz O., Factorization: little or great algorithm?, J. Phys. A: Math. Gen. 37 (2004),
10007–10035.
[34] Andrianov A.A., Cannata F., Nonlinear supersymmetry for spectral design in quantum mechanics,
J. Phys. A: Math. Gen. 37 (2004), 10297–10321, hep-th/0407077.
[35] Plyushchay M., Nonlinear supersymmetry: from classical to quantum mechanics, J. Phys. A: Math. Gen.
37 (2004), 10375–10384, hep-th/0402025.
[36] Sukumar C.V., Supersymmetric quantum mechanics and its applications, AIP Conf. Proc. 744 (2005),
166–235.
[37] Fernández D.J., Fernández-Garćıa N., Higher-order supersymmetric quantum mechanics, AIP Conf. Proc.
744 (2005), 236–273, quant-ph/0502098.
[38] Dong S.-H., Factorization method in quantum mechanics, Fundamental Theories of Physics, Vol. 150,
Springer, Dordrecht, 2007.
[39] Andrianov A.A., Sokolov A.V., Factorization of nonlinear supersymmetry in one-dimensional quantum me-
chanics. I. General classification of reducibility and analysis of the third-order algebra, J. Math. Sci. 143
(2007), 2707–2722, arXiv:0710.5738.
[40] Sokolov A.V., Factorization of nonlinear supersymmetry in one-dimensional quantum mechanics. II. Proofs
of theorems on reducibility, J. Math. Sci. 151 (2008), 2924–2936, arXiv:0903.2835.
[41] Fernández D.J., Supersymmetric quantum mechanics, AIP Conf. Proc. 1287 (2010), 3–36, arXiv:0910.0192.
[42] Fernández D.J., Glasser M.L., Nieto L.M., New isospectral oscillator potentials, Phys. Lett. A 240 (1998),
15–20.
[43] Fernández D.J., Hussin V., Mielnik B., A simple generation of exactly solvable anharmonic oscillators, Phys.
Lett. A 244 (1998), 309–316.
[44] Rosas-Ortiz J.O., New families of isospectral hydrogen-like potentials, J. Phys. A: Math. Gen. 31 (1998),
L507–L513, quant-ph/9803029.
[45] Rosas-Ortiz J.O., Exactly solvable hydrogen-like potentials and factorization method, J. Phys. A: Math.
Gen. 31 (1998), 10163–10179, quant-ph/9806020.
[46] Contreras-Astorga A., Fernández D.J., Supersymmetric partners of the trigonometric Pöschl–Teller poten-
tials, J. Phys. A: Math. Theor. 41 (2008), 475303, 18 pages, arXiv:0809.2760.
[47] Dı́az J.I., Negro J., Nieto L.M., Rosas-Ortiz O., The supersymmetric modified Pöschl–Teller and delta-well
potentials, J. Phys. A: Math. Gen. 32 (1999), 8447–8460, quant-ph/9910017.
[48] Uchino T., Tsutsui I., Supersymmetric quantum mechanics with a point singularity, Nuclear Phys. B 662
(2003), 447–460, quant-ph/0210084.
[49] Uchino T., Tsutsui I., Supersymmetric quantum mechanics under point singularities, J. Phys. A: Math.
Gen. 36 (2003), 6821–6846, hep-th/0302089.
[50] Fülöp T., Tsutsui I., Cheon T., Spectral properties on a circle with a singularity, J. Phys. Soc. Japan 72
(2003), 2737–2746, quant-ph/0307002.
[51] Correa F., Nieto L.M., Plyushchay M.S., Hidden nonlinear su(2|2) superunitary symmetry of N = 2 su-
perextended 1D Dirac delta potential problem, Phys. Lett. B 659 (2008), 746–753, arXiv:0707.1393.
[52] Correa F., Jakubsky V., Nieto L.M., Plyushchay M.S., Self-isospectrality, special supersymmetry, and their
effect on the band structure, Phys. Rev. Lett. 101 (2008), 030403, 4 pages, arXiv:0801.1671.
[53] Correa F., Jakubsky V., Plyushchay M.S., Finite-gap systems, tri-supersymmetry and self-isospectrality,
J. Phys. A: Math. Theor. 41 (2008), 485303, 35 pages, arXiv:0806.1614.
[54] Correa F., Plyushchay M.S., Hidden supersymmetry in quantum bosonic systems, Ann. Physics 322 (2007),
2493–2500, hep-th/0605104.
[55] Jakubsky V., Nieto L.M., Plyushchay M.S., The origin of hidden supersymmetry, Phys. Lett. B 692 (2010),
51–56, arXiv:1004.5489.
[56] Andrianov A.A., Ioffe M.V., Spiridonov V., Higher-derivative supersymmetry and the Witten index, Phys.
Lett. A 174 (1993), 273–279, hep-th/9303005.
[57] Andrianov A.A., Ioffe M.V., Cannata F., Dedonder J.-P., Second order derivative supersymmetry, q defor-
mations and the scattering problem, Internat. J. Modern Phys. A 10 (1995), 2683–2702, hep-th/9404061.
http://dx.doi.org/10.1088/0305-4470/37/43/001
http://dx.doi.org/10.1088/0305-4470/37/43/019
http://arxiv.org/abs/hep-th/0407077
http://dx.doi.org/10.1088/0305-4470/37/43/024
http://arxiv.org/abs/hep-th/0402025
http://arxiv.org/abs/quant-ph/0502098
http://dx.doi.org/10.1007/s10958-007-0158-6
http://arxiv.org/abs/0710.5738
http://dx.doi.org/10.1007/s10958-008-9009-3
http://arxiv.org/abs/0903.2835
http://dx.doi.org/10.1063/1.3507423
http://arxiv.org/abs/0910.0192
http://dx.doi.org/10.1016/S0375-9601(98)00068-1
http://dx.doi.org/10.1016/S0375-9601(98)00298-9
http://dx.doi.org/10.1016/S0375-9601(98)00298-9
http://dx.doi.org/10.1088/0305-4470/31/27/003
http://arxiv.org/abs/quant-ph/9803029
http://dx.doi.org/10.1088/0305-4470/31/50/012
http://dx.doi.org/10.1088/0305-4470/31/50/012
http://arxiv.org/abs/quant-ph/9806020
http://dx.doi.org/10.1088/1751-8113/41/47/475303
http://arxiv.org/abs/0809.2760
http://dx.doi.org/10.1088/0305-4470/32/48/308
http://arxiv.org/abs/quant-ph/9910017
http://dx.doi.org/10.1016/S0550-3213(03)00352-3
http://arxiv.org/abs/quant-ph/0210084
http://dx.doi.org/10.1088/0305-4470/36/24/318
http://dx.doi.org/10.1088/0305-4470/36/24/318
http://arxiv.org/abs/hep-th/0302089
http://dx.doi.org/10.1143/JPSJ.72.2737
http://arxiv.org/abs/quant-ph/0307002
http://dx.doi.org/10.1016/j.physletb.2007.11.046
http://arxiv.org/abs/0707.1393
http://dx.doi.org/10.1103/PhysRevLett.101.030403
http://arxiv.org/abs/0801.1671
http://dx.doi.org/10.1088/1751-8113/41/48/485303
http://arxiv.org/abs/0806.1614
http://dx.doi.org/10.1016/j.aop.2006.12.002
http://arxiv.org/abs/hep-th/0605104
http://dx.doi.org/10.1016/j.physletb.2010.07.014
http://arxiv.org/abs/1004.5489
http://dx.doi.org/10.1016/0375-9601(93)90137-O
http://dx.doi.org/10.1016/0375-9601(93)90137-O
http://arxiv.org/abs/hep-th/9303005
http://dx.doi.org/10.1142/S0217751X95001261
http://arxiv.org/abs/hep-th/9404061
14 D.J. Fernández C., M. Gadella and L.M. Nieto
[58] Bagrov V.G., Samsonov B.F., Darboux transformation of the Schrödinger equation, Phys. Particles Nuclei
28 (1997), 374–397.
[59] Fernández D.J., SUSUSY quantum mechanics, Internat. J. Modern Phys. A 12 (1997), 171–176,
quant-ph/9609009.
[60] Flügge S., Practical quantum mechanics, Springer-Verlag, Berlin, 1999.
[61] Mielnik B., Nieto L.M., Rosas-Ortiz O., The finite difference algorithm for higher order supersymmetry,
Phys. Lett. A 269 (2000), 70–78, quant-ph/0004024.
[62] Fernández D.J., Salinas-Hernández E., The confluent algorithm in second order supersymmetric quantum
mechanics, J. Phys. A: Math. Gen. 36 (2003), 2537–2543, quant-ph/0303123.
[63] Fernández D.J., Salinas-Hernández E., Wronskian formula for confluent second-order supersymmetric quan-
tum mechanics, Phys. Lett. A 338 (2005), 13–18, quant-ph/0502147.
[64] Fernández D.J., Muñoz R., Ramos A., Second order SUSY transformations with ‘complex energies’, Phys.
Lett. A 308 (2003), 11–16, quant-ph/0212026.
[65] Rosas-Ortiz O., Muñoz R., Non-Hermitian SUSY hydrogen-like Hamiltonians with real spectra, J. Phys. A:
Math. Gen. 36 (2003), 8497–8506, quant-ph/0302190.
[66] Fernández-Garćıa N., Rosas-Ortiz O., Gamow–Siegert functions and Darboux-deformed short range poten-
tials, Ann. Physics 323 (2008), 1397–1414, arXiv:0810.5597.
http://www.ams.org/leavingmsn?url=http://dx.doi.org/10.1134/1.953045
http://dx.doi.org/10.1142/S0217751X97000232
http://arxiv.org/abs/quant-ph/9609009
http://dx.doi.org/10.1016/S0375-9601(00)00226-7
http://arxiv.org/abs/quant-ph/0004024
http://dx.doi.org/10.1088/0305-4470/36/10/313
http://arxiv.org/abs/quant-ph/0303123
http://dx.doi.org/10.1016/j.physleta.2005.02.020
http://arxiv.org/abs/quant-ph/0502147
http://dx.doi.org/10.1016/S0375-9601(02)01779-6
http://dx.doi.org/10.1016/S0375-9601(02)01779-6
http://arxiv.org/abs/quant-ph/0212026
http://dx.doi.org/10.1088/0305-4470/36/31/311
http://dx.doi.org/10.1088/0305-4470/36/31/311
http://arxiv.org/abs/quant-ph/0302190
http://dx.doi.org/10.1016/j.aop.2007.11.002
http://arxiv.org/abs/0810.5597
1 Introduction
2 Solution of the Schrödinger equation
3 First-order SUSY transformations
4 Second-order SUSY transformations
4.1 Confluent case mnr00,fs03
4.2 Complex case fmr03,rm03,fr08
4.3 Real case
5 Conclusions
References
|
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| language | English |
| last_indexed | 2025-12-07T16:01:56Z |
| publishDate | 2011 |
| publisher | Інститут математики НАН України |
| record_format | dspace |
| spelling | David J. Fernández C. Gadella, M. Nieto, L.M. 2019-02-11T15:26:18Z 2019-02-11T15:26:18Z 2011 Supersymmetry Transformations for Delta Potentials / David J. Fernández C., M. Gadella, L.M. Nieto // Symmetry, Integrability and Geometry: Methods and Applications. — 2011. — Т. 7. — Бібліогр.: 66 назв. — англ. 1815-0659 2010 Mathematics Subject Classification: 81Q60 DOI:10.3842/SIGMA.2011.029 https://nasplib.isofts.kiev.ua/handle/123456789/146801 We make a detailed study of the first and second-order SUSY partners of a one-dimensional free Hamiltonian with a singular perturbation proportional to a Dirac delta function. It is shown that the second-order transformations increase the spectral manipulation possibilities offered by the standard first-order supersymmetric quantum mechanics. This paper is a contribution to the Proceedings of the Workshop “Supersymmetric Quantum Mechanics and Spectral Design” (July 18–30, 2010, Benasque, Spain). The full collection is available at http://www.emis.de/journals/SIGMA/SUSYQM2010.html. Partial financial support is acknowledged to the Spanish Junta de Castilla y Le´on (Project GR224) and the Ministry of Science and Innovation (Projects MTM2009-10751 and FPA2008-04772-E). DJFC acknowledges the support of Conacyt. en Інститут математики НАН України Symmetry, Integrability and Geometry: Methods and Applications Supersymmetry Transformations for Delta Potentials Article published earlier |
| spellingShingle | Supersymmetry Transformations for Delta Potentials David J. Fernández C. Gadella, M. Nieto, L.M. |
| title | Supersymmetry Transformations for Delta Potentials |
| title_full | Supersymmetry Transformations for Delta Potentials |
| title_fullStr | Supersymmetry Transformations for Delta Potentials |
| title_full_unstemmed | Supersymmetry Transformations for Delta Potentials |
| title_short | Supersymmetry Transformations for Delta Potentials |
| title_sort | supersymmetry transformations for delta potentials |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/146801 |
| work_keys_str_mv | AT davidjfernandezc supersymmetrytransformationsfordeltapotentials AT gadellam supersymmetrytransformationsfordeltapotentials AT nietolm supersymmetrytransformationsfordeltapotentials |