Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation...

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Main Authors: Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., Mishchenko, A.
Format: Article
Published: American Association for the Advancement of Science 2016
Online Access:https://eprints.nottingham.ac.uk/39486/
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author Wallbank, J.R.
Ghazaryan, D.
Misra, A.
Cao, Y.
Tu, J.S.
Piot, B.A.
Potemski, M.
Pezzini, S.
Wiedmann, S.
Zeitler, U.
Lane, T.L.M.
Morozov, S.V.
Greenaway, M.T.
Eaves, Laurence
Geim, A.K.
Fal'ko, V.I.
Novoselov, K.S.
Mishchenko, A.
author_facet Wallbank, J.R.
Ghazaryan, D.
Misra, A.
Cao, Y.
Tu, J.S.
Piot, B.A.
Potemski, M.
Pezzini, S.
Wiedmann, S.
Zeitler, U.
Lane, T.L.M.
Morozov, S.V.
Greenaway, M.T.
Eaves, Laurence
Geim, A.K.
Fal'ko, V.I.
Novoselov, K.S.
Mishchenko, A.
author_sort Wallbank, J.R.
building Nottingham Research Data Repository
collection Online Access
description Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene’s Dirac electrons in a particular quantum chiral state in a selected valley.
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publisher American Association for the Advancement of Science
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spelling nottingham-394862020-05-04T18:07:45Z https://eprints.nottingham.ac.uk/39486/ Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures Wallbank, J.R. Ghazaryan, D. Misra, A. Cao, Y. Tu, J.S. Piot, B.A. Potemski, M. Pezzini, S. Wiedmann, S. Zeitler, U. Lane, T.L.M. Morozov, S.V. Greenaway, M.T. Eaves, Laurence Geim, A.K. Fal'ko, V.I. Novoselov, K.S. Mishchenko, A. Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene’s Dirac electrons in a particular quantum chiral state in a selected valley. American Association for the Advancement of Science 2016-08-05 Article PeerReviewed Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S. and Mishchenko, A. (2016) Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures. Science, 353 (6299). pp. 575-579. ISSN 1095-9203 http://science.sciencemag.org/content/353/6299/575 doi:10.1126/science.aaf4621 doi:10.1126/science.aaf4621
spellingShingle Wallbank, J.R.
Ghazaryan, D.
Misra, A.
Cao, Y.
Tu, J.S.
Piot, B.A.
Potemski, M.
Pezzini, S.
Wiedmann, S.
Zeitler, U.
Lane, T.L.M.
Morozov, S.V.
Greenaway, M.T.
Eaves, Laurence
Geim, A.K.
Fal'ko, V.I.
Novoselov, K.S.
Mishchenko, A.
Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures
title Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures
title_full Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures
title_fullStr Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures
title_full_unstemmed Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures
title_short Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures
title_sort tuning the valley and chiral quantum state of dirac electrons in van der waals heterostructures
url https://eprints.nottingham.ac.uk/39486/
https://eprints.nottingham.ac.uk/39486/
https://eprints.nottingham.ac.uk/39486/