Heavy-hole states in germanium hut wires Journal Article

Author(s): Watzinger, Hannes; Kloeffel, Christoph; Vukušić, Lada; Rossell, Marta D; Sessi, Violetta; Kukučka, Josip; Kirchschlager, Raimund; Lausecker, Elisabeth; Truhlar, Alisha; Glaser, Martin; Rastelli, Armando; Fuhrer, Andreas; Loss, Daniel; Katsaros, Georgios
Article Title: Heavy-hole states in germanium hut wires
Affiliation IST Austria
Abstract: Hole spins have gained considerable interest in the past few years due to their potential for fast electrically controlled qubits. Here, we study holes confined in Ge hut wires, a so-far unexplored type of nanostructure. Low-temperature magnetotransport measurements reveal a large anisotropy between the in-plane and out-of-plane g-factors of up to 18. Numerical simulations verify that this large anisotropy originates from a confined wave function of heavy-hole character. A light-hole admixture of less than 1% is estimated for the states of lowest energy, leading to a surprisingly large reduction of the out-of-plane g-factors compared with those for pure heavy holes. Given this tiny light-hole contribution, the spin lifetimes are expected to be very long, even in isotopically nonpurified samples.
Keywords: quantum dot; Germanium; g-factor; heavy hole; Luttinger−Kohn Hamiltonian
Journal Title: Nano Letters
Volume: 16
Issue 11
ISSN: 1530-6992
Publisher: American Chemical Society  
Date Published: 2016-09-22
Start Page: 6879
End Page: 6885
Copyright Statement: CC-BY
DOI: 10.1021/acs.nanolett.6b02715
Notes: The work was supported by the EC FP7 ICT project SiSPIN no. 323841, the EC FP7 ICT project PAMS no. 610446, the ERC Starting Grant no. 335497, the FWF-I-1190-N20 project, and the Swiss NSF. We acknowledge F. Scha ̈ ffl er for fruitful discussions related to the hut wire growth and for giving us access to the molecular beam epitaxy system, M. Schatzl for her support in electron beam lithography, and V. Jadris ̌ ko for helping us with the COMSOL simulations. Finally, we thank G. Bauer for his continuous support.
Open access: yes (OA journal)