Aharonov-Bohm Interference and Phase-Coherent Surface-State Transport in Topological Insulator Rings

Nano Letters, vol. 23, pp. 6347–6353

Abstract

High Resolution Image Download MS PowerPoint Slide We present low-temperature magnetotransport measurements on selectively grown Sb 2 Te 3 -based topological insulator ring structures. These devices display clear Aharonov-Bohm oscillations in the conductance originating from phase-coherent transport around the ring. The temperature dependence of the oscillation amplitude indicates that the Aharonov-Bohm oscillations originate from ballistic transport along the ring arms. We attribute these oscillations to the topological surface states. Further insight into the phase coherence is gained by comparing with similar Aharonov-Bohm-type oscillations in topological insulator nanoribbons exposed to an axial magnetic field. Here, quasi-ballistic phase-coherent transport is confirmed for closed-loop topological surface states in the transverse direction enclosing the nanoribbon. In contrast, the appearance of universal conductance fluctuations indicates phase-coherent transport in the diffusive regime, which is attributed to bulk carrier transport. Thus, it appears that even in the presence of diffusive p -type charge carriers in Aharonov-Bohm ring structures, phase-coherent quasi-ballistic transport of topological surface states is maintained over long distances.

Authors 12

1. Gerrit Behner corresponding Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

2. Abdur Rehman Jalil Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

3. Dennis Heffels Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

4. Jonas Kölzer Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

5. Kristof Moors Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

6. Jonas Mertens Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

7. Erik Zimmermann Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

8. Gregor Mußler Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

9. Peter Schüffelgen Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

10. Hans Luth Aachen JARA-Fundamentals of Future Information Technology

    Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

    Affiliation as printed

    JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

    Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

11. Detlev Grützmacher Aachen JARA-Fundamentals of Future Information Technology

    Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

    Affiliation as printed

    JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

    Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

12. Thomas Schäpers corresponding Aachen JARA-Fundamentals of Future Information Technology

    Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

    Affiliation as printed

    JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

    Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany