Effects of geometry on spin-orbit Kramers states in semiconducting nanorings
| Autor: | Francica, G., Gentile, P., Cuoco, M. |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | EPL, 127 (2019) 30001 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1209/0295-5075/127/30001 |
| Popis: | The holonomic manipulation of spin-orbital degenerate states, encoded in the Kramers doublet of narrow semiconducting channels with spin-orbit interaction, is shown to be intimately intertwined with the geometrical shape of the nanostructures. The presence of doubly degenerate states is not sufficient to guarantee a non-trivial mixing by only changing the Rashba spin-orbit coupling. We demonstrate that in nanoscale quantum rings the combination of arbitrary inhomogeneous curvature and adiabatic variation of the spin-orbit amplitude, e.g. through electric-field gating, can be generally employed to get non-trivial combinations of the degenerate states. Shape symmetries of the nanostructure act to constrain the adiabatic quantum evolution. While for circular rings the geometric phase is not generated along a non-cyclic path in the parameters space, remarkably, for generic mirror-symmetric shape deformed rings the spin-orbit driving can lead to a series of dynamical quantum phase transitions. We explicitly show this occurrence and propose a route to detect such topological transitions by measuring a variation of the electron tunneling amplitude into the semiconducting channel. Comment: 5 pages, 3 figures |
| Databáze: | arXiv |
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