Berlin 2015 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 31: Topological insulators: Transport (HL with DS/MA/O/TT)

DS 31.2: Vortrag

Mittwoch, 18. März 2015, 12:00–12:15, ER 270

Aharonov-Bohm oscillations in quantum wire of topological insulator — •Louis Veyrat¹, Joseph Dufouleur¹, Romain Giraud¹, Emmanouil Xypakis², Jens Bardarson², Christian Nowka¹, Silke Hampel¹, and Bernd Büchner¹ — ¹IFW-Dresden — ²MPIPKS

Studying Aharonov-Bohm (AB) effect in a nanowire of topological insulator is a convenient way to reveal the specific properties of the topological surface states (SS), which are spin-chiral Dirac fermions. In the short perimeter limit, we evidenced in a previous work the ballistic transport of the SS in the perimeter of the nanowire, revealed by the temperature dependance of the phase coherence length [1] and showing the weak scattering effect of disorder on Dirac fermions. The quantum transverse confinement of SS is further revealed by the observation of non-universal conductance fluctuations. In the longer perimeter limit, we surprisingly find that the transport remains ballistic in the perimeter, despite the presence of disorder. The interaction with disorder is revealed by specific phase-jump of the AB oscillations under transverse magnetic field.

[1] Dufouleur et al., Phys. Rev. Lett. 110, 186806 (2013)