Interaction effects in a microscopic quantum wire model with strong spin-orbit interaction

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Date
2017-06Type
- Journal Article
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Abstract
We investigate the effect of strong interactions on the spectral properties of quantum wires with strong Rashba spin–orbit (SO) interaction in a magnetic field, using a combination of matrix product state and bosonization techniques. Quantum wires with strong Rashba SO interaction and magnetic field exhibit a partial gap in one-half of the conducting modes. Such systems have attracted wide-spread experimental and theoretical attention due to their unusual physical properties, among which are spin-dependent transport, or a topological superconducting phase when under the proximity effect of an s-wave superconductor. As a microscopic model for the quantum wire we study an extended Hubbard model with SO interaction and Zeeman field. We obtain spin resolved spectral densities from the real-time evolution of excitations, and calculate the phase diagram. We find that interactions increase the pseudo gap at k = 0 and thus also enhance the Majorana-supporting phase and stabilize the helical spin order. Furthermore, we calculate the optical conductivity and compare it with the low energy spiral Luttinger liquid result, obtained from field theoretical calculations. With interactions, the optical conductivity is dominated by an excotic excitation of a bound soliton–antisoliton pair known as a breather state. We visualize the oscillating motion of the breather state, which could provide the route to their experimental detection in e.g. cold atom experiments. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000191714Publication status
publishedExternal links
Journal / series
New Journal of PhysicsVolume
Pages / Article No.
Publisher
Institute of Physics Publishing Ltd.Subject
DMRG; matrix product states; spin-orbit interaction; Luttinger liquid; bosonization; Majorana; strong correlationsRelated publications and datasets
Is new version of: http://hdl.handle.net/20.500.11850/126094
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Citations
Cited null times in
Web of Science
Cited 5 times in
Scopus
ETH Bibliography
yes
Altmetrics