Regensburg 2013 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 29: Transport: Quantum Dots, Wires, Point Contacts 3 (jointly with HL)
TT 29.8: Talk
Tuesday, March 12, 2013, 11:45–12:00, H20
Helical nuclear spin order and conduction reduction in two subband quantum wires — •Tobias Meng and Daniel Loss — Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
In quantum wires, the hyperfine coupling between conduction electrons and nuclear spins can lead to an ordering of the latter at low temperatures. This order acts back onto the electrons and gaps out part of their spectrum. In the presence of two subbands with distinct Fermi momenta kF1 and kF2, we discuss how the nuclear spins order in a superposition of two helices with pitches π/kF1 and π/kF2, thus exhibiting a beating patter. This ordering results in a reduction of the electronic conductance in two steps of e2/h upon lowering the temperature.