SEMINARIUM INSTYTUTOWE

Dnia: 23.03.2016 roku (środa)
o godzinie 13:00 w auli Instytutu

referat pt.:

Exact non-adiabatic non-Abelian holonomic qubit manipulation

wygłosi

prof. Anton Ramsak

Faculty of Mathematics and Physics, University of Ljubljana, Slovenia

A brief introduction to the concept of geometric phases in classical and quantum mechanics will be given, from the Hannay angle to the Berry phase and to the non-adiabatic non-Abelian Anandan phase. The motivation is the manipulation of electron spin, in particular, by locally applying external electric fields.
Next we will present an exact solution for the wavefunction of an electron in a semiconductor quantum wire with spin-orbit interaction and driven by external time-dependent harmonic confining potential [1], which enables non-adiabatic spin manipulation [2]. The generalization of the formalism to mesoscopic ring systems opens the possibility to perform arbitrary qubit transformations on the Bloch sphere [3].
[1] T. Čadež, J. H. Jefferson, and A. Ramšak, New J. Phys. 15, 013029 (2013).
[2] T. Čadež, J. H. Jefferson, and A. Ramšak, Phys. Rev. Lett. 112, 150402 (2014).
[3] A. Kregar, J. H. Jefferson, and A. Ramšak, Phys. Rev. B 93, 075432 (2016); A. Kregar and A. Ramšak, arXiv:1512.07986.