Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire

Electron transport through Majorana nanowire with strongly asymmetric couplings to normal metal leads is
 considered. In three terminal geometry (electrically grounded nanowire) it is shown that the presence of unbiased
 electrode restores zero-bias anomaly even for strong Majorana e...

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Published in:Физика низких температур
Date:2016
Main Authors: Shkop, A.D., Parafilo, A.V., Krive, I.V., Shekhter, R.I.
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Language:English
Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2016
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Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/128507
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Cite this:Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire / A.D. Shkop, A.V. Parafilo, I.V. Krive, R.I. Shekhter // Физика низких температур. — 2016. — Т. 42, № 4. — С. 398–402. — Бібліогр.: 12 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Shkop, A.D.
Parafilo, A.V.
Krive, I.V.
Shekhter, R.I.
author_facet Shkop, A.D.
Parafilo, A.V.
Krive, I.V.
Shekhter, R.I.
citation_txt Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire / A.D. Shkop, A.V. Parafilo, I.V. Krive, R.I. Shekhter // Физика низких температур. — 2016. — Т. 42, № 4. — С. 398–402. — Бібліогр.: 12 назв. — англ.
collection DSpace DC
container_title Физика низких температур
description Electron transport through Majorana nanowire with strongly asymmetric couplings to normal metal leads is
 considered. In three terminal geometry (electrically grounded nanowire) it is shown that the presence of unbiased
 electrode restores zero-bias anomaly even for strong Majorana energy splitting. For effectively two-terminal
 geometry we show that electrical current through asymmetric Majorana junction is qualitatively different from
 the analogous current through a resonant (Breit–Wigner) level.
first_indexed 2025-12-07T17:41:01Z
format Article
fulltext Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 4, pp. 398–402 Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire A.D. Shkop1, A.V. Parafilo2, I.V. Krive1,3, and R.I. Shekhter4 1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Prospekt Nauky, Kharkiv 61103, Ukraine E-mail: Shkop@ilt.kharkov.ua 2The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34151 Trieste, Italy 3Ukraine Physical Department, V. N. Karazin National University, Kharkiv 61077, Ukraine 4Department of Physics, University of Gothenburg, SE-412 96 Göteborg, Sweden Received January 14, 2016, published online February 24, 2016 Electron transport through Majorana nanowire with strongly asymmetric couplings to normal metal leads is considered. In three terminal geometry (electrically grounded nanowire) it is shown that the presence of unbiased electrode restores zero-bias anomaly even for strong Majorana energy splitting. For effectively two-terminal geometry we show that electrical current through asymmetric Majorana junction is qualitatively different from the analogous current through a resonant (Breit–Wigner) level. PACS: 74.25.F– Transport properties; 73.23.–b Electronic transport in mesoscopic systems; 74.78.Na Mesoscopic and nanoscale systems. Keywords: electron tunneling, Majorana fermions, experimental setup. 1. Introduction Last years Majorana fermions attract a great attention in solid state physics. Firstly predicted by E. Majorana as a fermion particle that coincides with its own antiparticle, Majorana fermions reappeared in condensed matter in the form of Majorana bound states (MBS)-spinless zero-ener- gy subgap edge states in topological superconductors (see, e.g., [1] or review [2]), useful for fault-tolerant quantum computation [3]. By definition the creation and annihilation operators of MBS coincide, † = jjγ γ . Being a «half» of a Dirac fermion (its hermitian and anti-hermitian parts), Majorana fermions obey a Clifford algebra, { , } = 2 .i k kiγ γ δ Two MBS localized on the opposite sides of topological superconductor form a highly nonlocal Dirac fermion, 2 † 2 1 2= ( ) / 2, = ( ) = 0c i c cγ + γ . This nonlocality leads to unusual electron transport through Majorana bound states. In particular, electron tunneling in Majorana systems could be very different from resonant level electron tunneling even in the case when Majorana hybridization 1 2Mε γ γ ( Mε is Majorana splitting energy) is taken into account and MBS are splitted into two fermion levels. The presence of substrate superconductor introduces additional (Andreev) channel of electron tunneling and supports electron hole symmetry. Both those properties result in electron tunnel- ing through MBS which strongly differs from ordinary re- sonant electron tunneling described by Breit–Wigner trans- mision probability. Many efforts were spent to theoretically treat these to- pological modes and distinguish them from «ordinary» excitations in experiment which could mimic the properties of MBS (see, e.g., review [2]). A promising venue in expe- rimental observation of Majorana fermion is the tunneling experiments where electrons tunnel through MBS which provides the only possible channel for a subgap electrical current at low bias voltages. It is already known that Majorana fermions lead to a new transport phenomena — resonant Andreev reflection which manifested in zero-bias peak in differential conductance for normal metal/topological superconductor junction [5]. Although various properties of electron tunnel transport through Majorana bound states have been already studied for two-terminal [6–8] and three-terminal [9–11] devices, we can add to this knowledge new results concerning © A.D. Shkop, A.V. Parafilo, I.V. Krive, and R.I. Shekhter, 2016 Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire specific properties of asymmetric Majorana tunnel junction with strongly different coupling strengths to the normal metal leads. For this reasons we consider experimental setup (see Fig. 1) where an electrically grounded nanowire (i.e., 1D wire on top of s-wave superconductor) is tunnelly coupled to a fixed normal metal electrode (L-electrode) and to a movable tip of scanning microscope (R-electrode). In real experiment Majorana bound states are supposed to be hosted at the ends of semiconducting wire on a top of ordinary s-wave superconductor when proximity effect, strong spin-orbit interaction and external magnetic field work together to form effectively spinless regime of elec- tron transport deep inside the superconducting gap. Our purpose here is to study transmission properties of topo- logical superconductor with two Majorana modes weakly coupled to the normal metal leads. For electrically grounded superconductor the currents through left (L) and right (R) tunnel contacts in the general case of asymmetric junction ,( ,L R L RΓ ≠ Γ Γ are the coupling energies) are different even for equal biases L Rµ = µ << ∆ (∆ is the supercon- ducting gap). Each current depends both on LΓ and RΓ if Majorana splitting energy 0Mε ≠ . For this junction the linear conductances Gα ( = ,L Rα ) at low temperatures and = 0Mε reach maximum value 22 /e h , exhibiting zero-bias anomaly in the differential conductance (factor 2 is due to the contribution of Andreev tunneling) just like when ( ) 0L RΓ → (see Ref. 7). For 0Mε ≠ linear conductances are always finite 0Gα ≠ when both coupling energies ,L RΓ Γ are finite. In the limit ( ) 0,L RΓ → 0Mε ≠ the linear conductance vanishes, ( ) 0R LG → . We show that for strong- ly asymmetric junction <<L RΓ Γ and for finite Majorana energy splitting Mε in the range << <<L M RΓ ε Γ the pre- sence of the second MBS at the right end of the Majorana nanowire coupled to the unbiased R-electrode restores zero-bias anomaly in the differential conductance of the left contact. In the transport regime when Majorana nanowire is electrically isolated it is shown that electron current through a strongly asymmetric Majorana junction qualitatively dif- fers from the analogous current through Breit–Wigner resonant level. 2. Equations of motion and partial currents At first we calculate electric currents at three terminal system consisted of two metal leads and an electrically grounded Majorana nanowire. The full Hamiltonian is given by three terms = M tH H H Hα α + +∑ , where †= k kk k H c cα α ααε∑ is the Hamiltonian of normal leads with †( )k kc cα α being the electron annihilation (creation) operator for the α lead (L or R), quantum wire with Majorana edge states is described by effective low-energy Hamiltonian 1 2= ( / 2) ,M MH i ε γ γ which follows from Kitaev toy model [3], here 0exp ( / )M Lε ∝ − ξ is the splitting be- tween two zero-energy states (L is the length of the Majora- na quantum wire and 0ξ is the superconducting coherence length), and tH is the tunnel Hamiltonian. The tunnel Hamiltonian describing coupling between = /L Rα lead and topological superconductor is , = h.c.,t k k k H V cα α α α γ +∑ (1) here ( ) 1(2)=L Rγ γ , kVα is the effective amplitude of tunnel- ing which appears due to projection of superconductor electron-field operator onto the manifold of Majorana states, thus tunnel couplings are characterized by energy level width (see [2,7]) 2= 2 ( ) | |k k k Vα α αΓ πδ ε − ε∑ . The current operator in the α lead reads ( = 1 ) ( ) † ( ) = = 2 Im .kk k k k k dc c I t e e V c dt αα α α α α− γ∑ ∑ (2) By solving the Heisenberg equation of motion for ( )kc tα one finds ( )( ) = e e ( ) t i t i t tk kk k kc t c iV t dt′− ε − ε −∗α α α α α α −∞ ′ ′− γ∫ . (3) Then after substitution it into Heisenberg equation for Majorana operators ( ) = [ , ]t i Hα αγ γ (4) we obtain matrix equation for them ( ) 2 ( ) ( ) = , ( ) 2 ( ) ( ) L L M L L R M R R R t t t t t t γ − Γ ε γ ξ       +      γ −ε − Γ γ ξ         (5) Fig. 1. A schematic picture of Majorana nanowire with control- lable coupling to the leads. Tip of scanning tunneling microscope (STM) at the right end of nanowire enables one to vary the coupl- ing strenght RΓ . Electrical potentials of the leads = ,eVα αµ = ,L Rα are counted from the electrical potential 0µ = of the electrically grounded topological superconductor. UL ΓL µL µ = 0 ΓR µRMBS STM UR Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 4 399 A.D. Shkop, A.V. Parafilo, I.V. Krive, and R.I. Shekhter where ( ) = 2 e h.c.i tkk k k t i V c − εα α α αξ − +∑ After straightforward calculation one finds Majorana ope- rators 2 ( ) = e i t Lk RLkL Lk Lk Lk i t V c − ε ε + Γ γ + ∆∑ e h.c.i t MRkRk Rk Rk i V c − ε ε + + ∆∑ , (6) 2 ( ) = e i t Rk LRkR Rk Rk Rk i t V c − ε ε + Γ γ + ∆∑ e h.c.i t MLkLk Lk Lk i V c − ε ε + + ∆∑ (7) Here 2 2 22 = [ ( )] ( )k L R L R Miα α∆ ε + Γ + Γ + Γ − Γ − ε . Now with the help of Eqs. (2), (3), (6), (7) it is easy to get desired expression for the average currents ( )I I tα α= 〈 〉 , where ...〈 〉 is the thermodynamic average with the Hamil- tonian of noninteracting electrons in the leads. The average current = ( , )I I Tα αµ reads ( = 2h π) 2= ( ) tanh . 2 B eI d T h k T +∞ α α α −∞  µ − ω ω ω     ∫ (8) Here T is the temperature, = eVα αµ is the electric poten- tial counted from the Fermi energy and the transmission coefficient 2( )Tα ω takes the form 2 2 2 2 2 2 2 4(4 ) ( ) = , ( ) L R L R MT α α Γ Γ + Γ ω + Γ Γ ε ω ∆ ω (9) where 2 4 2 2 2 2( ) = 4 ( ) (4 )L R L R∆ ω ω + ω Γ + Γ + Γ Γ + 2 2 22( 4 ) .M M L R + ε ε − ω − Γ Γ  (10) 3. Differential conductance. Zero-bias anomaly Differential conductance in the low-temperature limit for each equally biased lead reads 22e= ( = )G T eV hα α ω (11) and when = 0, = 0MV ε it becomes 2 02 / = 2e h G . We see that ( , = 0) 0I T αµ ≡ for arbitrary tunneling rates LΓ and RΓ as it should be when the leads are not biased with respect to the ground. Notice the appearance for spinless electrons an extra overall factor 2 in Eq. (11) and hyper- bolic tangent in the current dependence on temperature and chemical potential instead of difference of Fermi distri- bution functions in the ordinary situation (Landauer–But- tiker formula). Both these features are related to the pre- sence of the substrate superconductor in electron transport through Majorana quantum wire. Factor 2 is due to appear- ance of addition channel (Andreev tunneling) in electron transport through MBS. Characteristic temperature and chemical potential dependence in Eq. (8) is usual for nor- mal metal–superconductor (MS) junctions. In the limiting case of a single MS contact ( = 0LΓ or = 0, = 0R MΓ ε ) our formulae for current and conductance are reduced to the corresponding expression in Ref. 7. In general case of asymmetric junction ( L RΓ ≠ Γ ) the currents in the left and right contacts are not equal, L RI I≠ (see also Ref. 11). It is reasonable to consider the limit when the total current to the ground vanishes, = = 0G L RI I I+ . Then one can speak about definite current from the left to right lead induced by voltage bias eV . With the help of our general formulae (8)–(10) we reproduce the expression for the current = LI I through a symmetric Majorana nanowire derived also in Refs. 9, 10. For asymmetric junction and/or asym- metric bias | | | |L Rµ ≠ µ the total current to the ground GI is not zero. Here we consider the dependence of dif- ferential conductance on =L eVµ in the case when = 0Rµ ( = 0, = = ( )R G LI I I I V , see also Ref. 11). It is straightfor- ward to find from our basic equations (8)–(10) the depen- dence of differential conductance on bias voltage at low temperatures 0( ) = 2 ( = )LG V G T eVω . In terms of dimension- less variables  = / 2 L RV V Γ Γ and / 2M M L Rε = ε Γ Γ dif- ferential conductance ( )G V takes the form   22 2 22 2 2 2 2 20 1 ( / )( ) = 2 (1 ) [( ) / ] M L R M L R L R M e VG V G e V + ε + Γ Γ + ε + Γ + Γ Γ Γ − ε    . (12) Particularly in the linear response 0V → Eq. (12) is simpl- ified 2 0 4 = . 2 4 L R L R M G G Γ Γ Γ Γ + ε (13) Thus for <<M L Rε Γ Γ differential conductance is 0/ 2 1G G → , while (0) = 0,G when = 0, >>R M LΓ ε Γ . It means that zero-bias Majorana signature 0(0) = 2G G disappears in a single contact junction if Majorana energy splitting >>M Lε Γ . Zero-bias peak is re-established for strongly asymmetric double contact junction >>R LΓ Γ and <<M L Rε Γ Γ when the total width of splitted Majorana levels exceeds the level splitting. In general the presence of even unbiased second contact enhances the current at low energies (temperature, bias voltage). 4. Electrically isolated Majorana nanowire Now we consider experimental setup when the super- conductor which supports Majorana nanowire is electric- ally isolated and the current through MBS is induced by the bias voltage =L R eVµ − µ . For a symmetric junc- tion ( = =L RΓ Γ Γ) this problem was studied in Refs. 9, 10. We have seen already that for symmetric electrically grounded junction and for symmetrically biased leads = = / 2L R eVµ −µ (only this case was considered in Ref. 10) the total current to the ground = = 0G L RI I I+ . So the cur- 400 Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 4 Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire rents through left and right contacts are equal, | | | |L RI I= . It does not matter whether superconductor is electrically grounded or not. This strategy can be applied also for asymmetric junc- tion. Now the equations = , ( ) = 0, =L R L R I eVα α α µ µ − µ∑ (14) determine electrical potentials αµ of the leads as a function of bias voltage V . It is evident that for small junction asymmetry | |<<L R L RΓ − Γ Γ + Γ the asymmetry in elec- trical potentials = L RV V Vδ + is small and weakly influ- ences the current. In the opposite limit of strong junction asymmetry (for definiteness we will assume >>L RΓ Γ ) elec- trical potentials strongly differ, | | << | |L RV V for all biases V and the current through the electrically isolated Majorana nanowire could be different comparing with the analogous current through resonant (Breit–Wigner) level. At first we consider low-temperature limit 0T → and a sufficiently long nanowire ( 0>>L ξ ) thus Majorana energy splitting can be neglected. In this case the problem can be easily solved analytically. When = 0Mε the transmission coefficient Tα depends (as it should be) only on its coupl- ing energy strength αΓ 2 2 2 4 = 4 T α α α Γ ω + Γ (15) and the corresponding currents take a simple form 2( ) = arctan . 2 e I α α α α α  Γ µ µ  π Γ  (16) For strongly asymmetric junction >>L RΓ Γ the solu- tion of Eq. (16) is 2 arctan 2L R R eV  µ Γ  Γ   (17) ( =R LeVµ − + µ ) and the current through electrically isolated Majorana nanowire is determined by the cor- responding current through the weakest link 2( ) = arctan 2 R R e eVI V  Γ  π Γ  . (18) According to Eq. (18) the current is saturated at >> ReV Γ to the value = ( ) /m RI eΓ  which coincides with corres- ponding maximum current through Breit–Wigner resonant level ( >>L RΓ Γ ). However unlike usual transport where saturation occurs at tot = L R LeV Γ Γ + Γ Γ  (for strong- ly asymmetric junction) in our case the current reaches its maximum value at a much more lower energies ReV Γ (see Fig. 2(b)). Now we consider the influence of finite Majorana splitt- ing Mε on current voltage characteristics. Our calculations show (see Fig. 2(b)) that «small» values of splitting energy <<M Lε Γ weakly influence I–V curves evaluated for = 0.Mε When Mε is of the order of LΓ the saturation of current curves occurs at energy scale s MeV ε end this I –V characteristic resembles the well-known ( )I V -dependence for electron tunneling through an asymmetric single-level quantum dot. Specific features of Majorana tunneling dis- appear. One can see the characteristic properties of Majorana tunneling also by analyzing the temperature dependence of conductance ( )G T . As it is well known (see, e.g., review [12]) the conductance at resonant tunneling at high temperatures Fig. 2. (a) Differential conductance for electrically grounded Majorana nanowire in units 2 0 = /G e h as a function of bias voltage normalized by the total width L RΓ + Γ : (i) solid curve demonstrates the zero-bias anomaly ( = 0RΓ , STM tip is moved to infinity, = 0Mε ); (ii) dotted curve corresponds to the case of strong splitting energy = 2M Lε Γ . Majorana signature 0( = 0) = 2G V G disappears and conductance peak shifts to non- zero voltages. When the second contact (right) with high trans- parency >>R LΓ Γ is introduced one can observe Majorana signature again, line for current dependence in this case coincides with solid line. (b) Current–voltage characteristics of electrically isolated strongly asymmetric Majorana nanowire / =R LΓ Γ = 0.001, = 0Mε (dash-dot), =M Lε Γ (solid), = 2M Lε Γ (dot). In strongly asymmetric system ( >>L RΓ Γ ) without level split- ting ( = 0Mε ), the current saturates at voltages of order of the smallest tunnel width RΓ , in contrast to conventional resonant tunneling, thus this dependence is highly nonlinear. / LeV Γ/ ( )L ReV Γ + Γ 1.0 0.5 10 2 3 4 5 (a) (b) 0 5 10 G G/ 0 2 1 /(e / ) R I Γ  Fig. 3. Temperature dependence of dimensionless conductance 2 0( = /G e h) of electrically isolated Majorana nanowire ( = 0)Mε : (i) dashed curve corresponds to symmetric junction =L RΓ Γ , (ii) solid curve describes strongly asymmetric junction 3/ = 10R L −Γ Γ . / ( )B L Rk T Γ + Γ 2 1 100 20 G G/ 0 Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 4 401 A.D. Shkop, A.V. Parafilo, I.V. Krive, and R.I. Shekhter scales as ~ /G TΓ (where / ( )L R L RΓ = Γ Γ Γ + Γ ) and the crossover temperature from T-independent regime of transport to 1/ T -scaling is determined by the total level width t L RΓ = Γ + Γ . Our calculations show (see Fig. 3) that for strongly asymmetric electrically isolated Majorana nanowire crossover temperature is determined by the weakest coupling and therefore the conductance is strongly suppressed by temperature even at a low temperatures. 5. Conclusions In summary we calculated electrical current through Majorana bound states for electrically grounded system end effectively electrically isolated Majorana nanowire. Our aim was to find specific features of electron tunneling in this system in the presence of finite Majorana energy splitting Mε which suppresses zero-bias anomaly in dif- ferential conductance. We show that the fingerprints of Majorana states can be easily revealed in tunneling experi- ments with strongly asymmetric Majorana junction. We suggested experimental setup where the strenght of MBS coupling to the leads can be controlled with the help of scanning tunneling microscope (STM). For three-ter- minal geometry (electrically grounded Majorana nanowire) it was shown that the presence of unbiased extra electrode strongly coupled to the nanowire increases electric current through Majorana bound states at low bias voltages. In particular in the case when Majorana energy splitting is in the range << <<L M RΓ ε Γ zero-bias anomaly in differ- ential conductance which is suppressed for two-terminal device ( = 0RΓ ) is restored when RΓ exceeds Mε . Unusual tunneling characteristics of Majorana bound states (MBS) can be observed even in the limit of vanish- ingly small Majorana energy splitting 0Mε → . It is known (see, e.g., [7]) that in this case transmission coefficient of electron tunneling through MBS takes the form of Breit– Wigner resonant tunneling probability. Therefore the pre- sence in the system resonant levels at Fermi energy (in particular, Kondo resonance) can mimic the properties of Majorana fermions. We showed that the tunneling cur- rent through electrically isolated Majorana nanowire (two- terminal device) with strongly different couplings to the leads is qualitatively distinct from the analogous current through resonant (Breit–Wigner) level. For sufficiently strong asymmetry the current is saturated at low bias volt- ages and the measured –I V characteristics will look like a step-function. The authors thanks S.I. Kulinich for fruitful discus- sions. A.S. and I.K. acknowledge financial support from the NAS of Ukraine (grant No. 4/15-H). A.P. thanks the Abdus Salam ICTP (Trieste, Italy) for financial support and hospitality. 1. L. Fu and C.L. Kane, Phys. Rev. Lett. 100, 096407 (2008). 2. J. Alicea, Rep. Prog. Phys. 75, 076501 (2012). 3. A.Yu. Kitaev, Physics-Uspekhi 44, 131 (2001). 4. A.R. Akhmerov, J. Nilsson, and C.W.J. Beenakker, Phys. Rev. Lett. 101, 120403 (2008). 5. K.T. Law, P.A. Lee, and T.K. Ng, Phys. Rev. Lett. 103, (2009). 6. M. Leijnse and K. Flensberg, Phys. Rev. B 84, 140501(R) (2011). 7. K. Flensberg, Phys. Rev. B 82, 180516(R) (2010). 8. Y. Asano and Y. Tanaka, Phys. Rev. B 87, 104513 (2013). 9. R. Hutzen, A. Zazunov, B. Braunecker, A. Levy Yeyati, and R. Egger, Phys. Rev. Lett. 109, 166403 (2012). 10. R. Lopez, M. Lee, L. Serra, and J. Lim, arXiv:1310.6282 (2013). 11. Jia-Bin You, Xiao-Qiang Shao, Qing-Jun Tong, A.H. Chan, C.H. Oh, and Vlatko Vedral, J. Phys.: Condens. Matter 27(22), 225302 (2015). 12. I.V. Krive, A. Palevski, R.I. Shekhter, and M. Jonson, Fiz. Nizk. Temp. 36, 155 (2010) [Low Temp. Phys. 36, 119 (2010)]. 402 Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 4 http://dx.doi.org/10.1103/PhysRevLett.100.096407 http://dx.doi.org/10.1088/0034-4885/75/7/076501 http://dx.doi.org/10.1070/1063-7869/44/10S/S29 http://dx.doi.org/10.1103/PhysRevLett.101.120403 http://dx.doi.org/10.1103/PhysRevLett.101.120403 http://dx.doi.org/10.1103/PhysRevLett.103.237001 http://dx.doi.org/10.1103/PhysRevB.84.140501 http://dx.doi.org/10.1103/PhysRevB.82.180516 http://dx.doi.org/10.1103/PhysRevB.87.104513 http://dx.doi.org/10.1103/PhysRevLett.109.166403 http://dx.doi.org/10.1103/PhysRevB.89.205418 http://dx.doi.org/10.1088/0953-8984/27/22/225302 http://dx.doi.org/10.1063/1.3319350 1. Introduction 2. Equations of motion and partial currents 3. Differential conductance. Zero-bias anomaly 4. Electrically isolated Majorana nanowire 5. Conclusions
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 0132-6414
language English
last_indexed 2025-12-07T17:41:01Z
publishDate 2016
publisher Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
record_format dspace
spelling Shkop, A.D.
Parafilo, A.V.
Krive, I.V.
Shekhter, R.I.
2018-01-10T15:00:19Z
2018-01-10T15:00:19Z
2016
Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire / A.D. Shkop, A.V. Parafilo, I.V. Krive, R.I. Shekhter // Физика низких температур. — 2016. — Т. 42, № 4. — С. 398–402. — Бібліогр.: 12 назв. — англ.
0132-6414
PACS: 74.25.F–, 73.23.–b, 74.78.Na
https://nasplib.isofts.kiev.ua/handle/123456789/128507
Electron transport through Majorana nanowire with strongly asymmetric couplings to normal metal leads is&#xd; considered. In three terminal geometry (electrically grounded nanowire) it is shown that the presence of unbiased&#xd; electrode restores zero-bias anomaly even for strong Majorana energy splitting. For effectively two-terminal&#xd; geometry we show that electrical current through asymmetric Majorana junction is qualitatively different from&#xd; the analogous current through a resonant (Breit–Wigner) level.
The authors thanks S.I. Kulinich for fruitful discussions.&#xd; A.S. and I.K. acknowledge financial support from&#xd; the NAS of Ukraine (grant No. 4/15-H). A.P. thanks the&#xd; Abdus Salam ICTP (Trieste, Italy) for financial support&#xd; and hospitality.
en
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
Физика низких температур
Электронные свойства проводящих систем
Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire
Article
published earlier
spellingShingle Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire
Shkop, A.D.
Parafilo, A.V.
Krive, I.V.
Shekhter, R.I.
Электронные свойства проводящих систем
title Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire
title_full Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire
title_fullStr Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire
title_full_unstemmed Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire
title_short Low-energy anomalies in electron tunneling through strongly asymmetric Majorana nanowire
title_sort low-energy anomalies in electron tunneling through strongly asymmetric majorana nanowire
topic Электронные свойства проводящих систем
topic_facet Электронные свойства проводящих систем
url https://nasplib.isofts.kiev.ua/handle/123456789/128507
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