Title: Mach-Zehnder interferometry using spin- and valley-polarized quantum Hall edge states in graphene

Abstract

Confined to a two-dimensional plane, electrons in a strong magnetic field travel along the edge in one-dimensional quantum Hall channels that are protected against backscattering. These channels can be used as solid-state analogs of monochromatic beams of light, providing a unique platform for studying electron interference. Electron interferometry is regarded as one of the most promising routes for studying fractional and non-Abelian statistics and quantum entanglement via two-particle interference. However, creating an edge-channel interferometer in which electron-electron interactions play an important role requires a clean system and long phase coherence lengths. We realize electronic Mach-Zehnder interferometers with record visibilities of up to 98% using spin- and valley-polarized edge channels that copropagate along a pn junction in graphene. We find that interchannel scattering between same-spin edge channels along the physical graphene edge can be used to form beamsplitters, whereas the absence of interchannel scattering along gate-defined interfaces can be used to form isolated interferometer arms. Surprisingly, our interferometer is robust to dephasing effects at energies an order of magnitude larger than those observed in pioneering experiments on GaAs/AlGaAs quantum wells. Lastly, our results shed light on the nature of edge-channel equilibration and open up new possibilities for studying exotic electron statisticsmore » and quantum phenomena.« less

Authors:

Wei, Di S. ^[1]; van der Sar, Toeno  ^[2];

• Search DOE PAGES for author "van der Sar, Toeno"
• Search DOE PAGES for ORCID "0000-0002-6197-4808"

Sanchez-Yamagishi, Javier D.  ^[3];

• Search DOE PAGES for author "Sanchez-Yamagishi, Javier D."
• Search DOE PAGES for ORCID "0000-0001-9703-6525"

Watanabe, Kenji  ^[4];

• Search DOE PAGES for author "Watanabe, Kenji"
• Search DOE PAGES for ORCID "0000-0003-3701-8119"

Taniguchi, Takashi ^[4]; Jarillo-Herrero, Pablo ^[5]; Halperin, Bertrand I.  ^[2];

• Search DOE PAGES for author "Halperin, Bertrand I."
• Search DOE PAGES for ORCID "0000-0002-6999-1039"

Yacoby, Amir  ^[6]

• Search DOE PAGES for author "Yacoby, Amir"
• Search DOE PAGES for ORCID "0000-0002-5737-7963"

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+ Show Author Affiliations

1. Harvard Univ., Cambridge, MA (United States). John A. Paulson School of Engineering and Applied Sciences
2. Harvard Univ., Cambridge, MA (United States). Dept. of Physics
3. Harvard Univ., Cambridge, MA (United States). Dept. of Physics; Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics
4. National Inst. for Materials Science (NIMS), Tsukuba (Japan). Advanced Materials Lab.
5. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics
6. Harvard Univ., Cambridge, MA (United States). John A. Paulson School of Engineering and Applied Sciences; Harvard Univ., Cambridge, MA (United States). Dept. of Physics

Publication Date:

Fri Aug 18 00:00:00 EDT 2017

Research Org.:

Harvard Univ., Cambridge, MA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; National Science Foundation (NSF)

OSTI Identifier:

1463899

Grant/Contract Number:  

SC0001819; DGE1144152; DMR-1231319; JP26248061; JP15K21722; JP25106006

Resource Type:

Accepted Manuscript

Journal Name:

Science Advances

Additional Journal Information:

Journal Volume: 3; Journal Issue: 8; Journal ID: ISSN 2375-2548

Publisher:

AAAS

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE