Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi
Performed full-relativistic DFT calculations have demonstrated that thin HgTe layers are metallic and, with increasing thickness, do not become insulators – either ordinary band insulators or topological insulators. The variations of the potential at the CdTe–HgTe interfaces are found to be negligib...
Gespeichert in:
| Datum: | 2021 |
|---|---|
| 1. Verfasser: | |
| Format: | Artikel |
| Sprache: | Englisch |
| Veröffentlicht: |
Publishing house "Academperiodika"
2021
|
| Schlagworte: | |
| Online Zugang: | https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2020235 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Ukrainian Journal of Physics |
Institution
Ukrainian Journal of Physics| _version_ | 1863131377273143296 |
|---|---|
| author | Yakovkin, I.N. |
| author_facet | Yakovkin, I.N. |
| author_sort | Yakovkin, I.N. |
| baseUrl_str | https://ujp.bitp.kiev.ua/index.php/ujp/oai |
| collection | OJS |
| datestamp_date | 2021-08-04T13:26:29Z |
| description | Performed full-relativistic DFT calculations have demonstrated that thin HgTe layers are metallic and, with increasing thickness, do not become insulators – either ordinary band insulators or topological insulators. The variations of the potential at the CdTe–HgTe interfaces are found to be negligible in comparison with those at the terminating surfaces of the CdTe–HgTe–CdTe films, so that the interfaces in fact do not form any potential well. It is shown that the interface-related bands of the CdTe–HgTe–CdTe films are situated well below EF, so that a dominant input into the density of states at EF and, therefore, to the conductivity is provided not by the interface states, but by the surface bands of the net layered system. It is reasonable therefore to consider an alternative interpretation of the reported thickness dependence of the conductivity of the system, such as the possible surface segregation of components or unavoidable contaminations, which seems much more realistic than the interpretation based on involving topological insulators and topologically protected surface states. |
| doi_str_mv | 10.15407/ujpe66.7.630 |
| first_indexed | 2025-10-02T01:17:19Z |
| format | Article |
| id | ujp2-article-2020235 |
| institution | Ukrainian Journal of Physics |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2025-10-02T01:17:19Z |
| publishDate | 2021 |
| publisher | Publishing house "Academperiodika" |
| record_format | ojs |
| spelling | ujp2-article-20202352021-08-04T13:26:29Z Surface and Interface Bands of the CdTe–HgTe–CdTe Heterostructure: Evidence of Metallicity Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi Yakovkin, I.N. surface states density functional calculations HgTe–CdTe layers surface states поверхневi стани DFT-розрахунки HgTe–CdTe шари Performed full-relativistic DFT calculations have demonstrated that thin HgTe layers are metallic and, with increasing thickness, do not become insulators – either ordinary band insulators or topological insulators. The variations of the potential at the CdTe–HgTe interfaces are found to be negligible in comparison with those at the terminating surfaces of the CdTe–HgTe–CdTe films, so that the interfaces in fact do not form any potential well. It is shown that the interface-related bands of the CdTe–HgTe–CdTe films are situated well below EF, so that a dominant input into the density of states at EF and, therefore, to the conductivity is provided not by the interface states, but by the surface bands of the net layered system. It is reasonable therefore to consider an alternative interpretation of the reported thickness dependence of the conductivity of the system, such as the possible surface segregation of components or unavoidable contaminations, which seems much more realistic than the interpretation based on involving topological insulators and topologically protected surface states. Проведенi повнорелятивiстськi DFT розрахунки продемонстрували, що тонкi шари HgTe є металевими i зi збiльшенням товщини не можуть стати iзоляторами – анi звичайними, анi топологiчними. Варiацiї потенцiалу на iнтерфейсах CdTe–HgTe виявляються незначними порiвняно з тими, що на зовнiшнiх поверхнях плiвок CdTe–HgTe–CdTe, так що iнтерфейси насправдi не утворюють потенцiального колодязя. Показано, що iнтерфейснi зони плiвок CdTe–HgTe–CdTe розташованi набагато нижче EF, так що домiнуючий внесок у густину станiв на EF, а отже i на провiднiсть, забезпечується не станами iнтерфейсу, а поверхневими зонами всiєї шаруватої системи. Тому пропонується розглянути альтернативну iнтерпретацiю повiдомленої залежностi провiдностi системи вiд товщини, наприклад, можливу поверхневу сегрегацiю компонентiв або неминучi забруднення, що здається набагато бiльш реалiстичним, нiж iнтерпретацiя, заснована на концепцiї топологiчних iзоляторiв. Publishing house "Academperiodika" 2021-08-04 Article Article Original Research Article (peer-reviewed) Оригінальна дослідницька стаття (з незалежним рецензуванням) application/pdf https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2020235 10.15407/ujpe66.7.630 Ukrainian Journal of Physics; Vol. 66 No. 7 (2021); 630 Український фізичний журнал; Том 66 № 7 (2021); 630 2071-0194 2071-0186 10.15407/ujpe66.7 en https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2020235/1865 Copyright (c) 2021 Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine |
| spellingShingle | поверхневi стани DFT-розрахунки HgTe–CdTe шари Yakovkin, I.N. Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi |
| title | Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi |
| title_alt | Surface and Interface Bands of the CdTe–HgTe–CdTe Heterostructure: Evidence of Metallicity |
| title_full | Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi |
| title_fullStr | Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi |
| title_full_unstemmed | Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi |
| title_short | Поверхневi та iнтерфейснi зони гетероструктури CdTe–HgTe–CdTe: докази металевостi |
| title_sort | поверхневi та iнтерфейснi зони гетероструктури cdte–hgte–cdte: докази металевостi |
| topic | поверхневi стани DFT-розрахунки HgTe–CdTe шари |
| topic_facet | surface states density functional calculations HgTe–CdTe layers surface states поверхневi стани DFT-розрахунки HgTe–CdTe шари |
| url | https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2020235 |
| work_keys_str_mv | AT yakovkinin surfaceandinterfacebandsofthecdtehgtecdteheterostructureevidenceofmetallicity AT yakovkinin poverhnevitainterfejsnizonigeterostrukturicdtehgtecdtedokazimetalevosti |