Heavy-Hole States in Germanium Hut Wires

• Published in: Nano letters Vol. 16; no. 11; pp. 6879 - 6885
• Main Authors: 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
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 09.11.2016
• Subjects: Letter; g-factor; quantum dot; Germanium; heavy hole; Luttinger−Kohn Hamiltonian
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.6b02715

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.