Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Probing spin helical surface states in topological HgTe nanowires. / Ziegler, J.; Kozlovsky, R.; Gorini, C. и др.
в: Physical Review B, Том 97, № 3, 035157, 29.01.2018.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Probing spin helical surface states in topological HgTe nanowires
AU - Ziegler, J.
AU - Kozlovsky, R.
AU - Gorini, C.
AU - Liu, M. H.
AU - Weishäupl, S.
AU - Maier, H.
AU - Fischer, R.
AU - Kozlov, D. A.
AU - Kvon, Z. D.
AU - Mikhailov, N.
AU - Dvoretsky, S. A.
AU - Richter, K.
AU - Weiss, D.
PY - 2018/1/29
Y1 - 2018/1/29
N2 - Nanowires with helical surface states represent key prerequisites for observing and exploiting phase-coherent topological conductance phenomena, such as spin-momentum locked quantum transport or topological superconductivity. We demonstrate in a joint experimental and theoretical study that gated nanowires fabricated from high-mobility strained HgTe, known as a bulk topological insulator, indeed preserve the topological nature of the surface states, that moreover extend phase-coherently across the entire wire geometry. The phase-coherence lengths are enhanced up to 5μm when tuning the wires into the bulk gap, so as to single out topological transport. The nanowires exhibit distinct conductance oscillations, both as a function of the flux due to an axial magnetic field and of a gate voltage. The observed h/e-periodic Aharonov-Bohm-type modulations indicate surface-mediated quasiballistic transport. Furthermore, an in-depth analysis of the scaling of the observed gate-dependent conductance oscillations reveals the topological nature of these surface states. To this end we combined numerical tight-binding calculations of the quantum magnetoconductance with simulations of the electrostatics, accounting for the gate-induced inhomogeneous charge carrier densities around the wires. We find that helical transport prevails even for strongly inhomogeneous gating and is governed by flux-sensitive high-angular momentum surface states that extend around the entire wire circumference.
AB - Nanowires with helical surface states represent key prerequisites for observing and exploiting phase-coherent topological conductance phenomena, such as spin-momentum locked quantum transport or topological superconductivity. We demonstrate in a joint experimental and theoretical study that gated nanowires fabricated from high-mobility strained HgTe, known as a bulk topological insulator, indeed preserve the topological nature of the surface states, that moreover extend phase-coherently across the entire wire geometry. The phase-coherence lengths are enhanced up to 5μm when tuning the wires into the bulk gap, so as to single out topological transport. The nanowires exhibit distinct conductance oscillations, both as a function of the flux due to an axial magnetic field and of a gate voltage. The observed h/e-periodic Aharonov-Bohm-type modulations indicate surface-mediated quasiballistic transport. Furthermore, an in-depth analysis of the scaling of the observed gate-dependent conductance oscillations reveals the topological nature of these surface states. To this end we combined numerical tight-binding calculations of the quantum magnetoconductance with simulations of the electrostatics, accounting for the gate-induced inhomogeneous charge carrier densities around the wires. We find that helical transport prevails even for strongly inhomogeneous gating and is governed by flux-sensitive high-angular momentum surface states that extend around the entire wire circumference.
KW - INSULATOR NANORIBBONS
KW - TRANSPORT
KW - CONDUCTORS
UR - http://www.scopus.com/inward/record.url?scp=85041195228&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.97.035157
DO - 10.1103/PhysRevB.97.035157
M3 - Article
AN - SCOPUS:85041195228
VL - 97
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 3
M1 - 035157
ER -
ID: 10452315