Affiliation
University of Basel
Title of work
Towards Hybrid Superconductor/Semiconductor Devices in Planar Germanium Heterostructures
Abstract
Coupling superconductors and semiconductors opens up the possibility to explore novel qubit types, such as the gate-tuneable transmon (gatemon) qubit [1, 2], Andreev bound states, their spins or topologically protected kinds such as the Majorana [3, 4].
Germanium/Silicon heterostructures provide a suitable platform for implementing those qubit types, due to the large elastic mean free path and Fermi level pinning close to the valence band [5]; anticipating a large coupling between superconductor and semiconductor. This coupling between s-like superconductor and p-like valence band states gives rise to an unconventional proximity effect, which is density tuneable, and provides the opportunity to investigate transitions to nontrivial topological phases [6]. While superconductor/semiconductor systems fabricated from nanowires or two dimensional electron gas heterostructures in Indium Arsenide have been studied extensively, superconductor/semiconductor devices based on holes have remained less explored.
We present our progress towards realizing a hybrid superconductor/semiconductor device in a two dimensional hole gas heterostructure.
References:
[1] de Lange, G. et al. Phys. Rev. Lett. 115, 127002 (2015).
[2] Larsen, T. W. et al. Phys. Rev. Lett. 115, 127001 (2015).
[3] Sau, J. D. et al., Phys. Rev. B 82, 214509 (2010).
[4] Mao, L. et al., Phys. Rev. Lett. 106, 157003 (2011).
[5] Dimoulas, A. et al., Appl. Phys. Lett. 89, 252110 (2006).
[6] Futterer, D.et al., Phys. Rev. B 84, 104526 (2011).