Ballistic One-Dimensional Holes with Strong g -Factor Anisotropy in Germanium

R. Mizokuchi (1) , R. Maurand (1) , F. Vigneau (1) , M. Myronov (2) , S. de Franceschi (1)

1 LaTEQS - Laboratoire de Transport Electronique Quantique et Supraconductivité
2 University of Warwick [Coventry]

We report experimental evidence of ballistic hole transport in one-dimensional quantum wires gate-defined in a strained SiGe/Ge/SiGe quantum well. At zero magnetic field, we observe conductance plateaus at integer multiples of 2e2/h. At finite magnetic field, the splitting of these plateaus by Zeeman effect reveals largely anisotropic g-factors, with absolute values below 1 in the quantum-well plane, and exceeding 10 out of plane. This g-factor anisotropy is consistent with a heavy-hole character of the propagating valence-band states, in line with a predominant confinement in the growth direction. Remarkably, we observe quantized ballistic conductance in device channels up to 600 nm long. These findings mark an important step towards the realization of novel devices for applications in quantum spintronics.

Mots clés: Ballistic transport; g-factor; germanium; holes; nanoelectronics; spintronics

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

R. Mizokuchi, R. Maurand, F. Vigneau, M. Myronov, S. de Franceschi. Ballistic One-Dimensional Holes with Strong g -Factor Anisotropy in Germanium. Nano Letters, 2018, 18 (8), pp.4861-4865. ⟨10.1021/acs.nanolett.8b01457⟩. ⟨hal-02083645⟩