Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 23: Quantum Information Systems
(Joint session of HL, MA, O and TT organized by HL)

TT 23.3: Vortrag

Dienstag, 8. März 2016, 10:00–10:15, H15

Higher Order Spin Correlation in Semi-Conductor Quantum Dots — •Nina Fröhling, Jan Böker, and Frithjof Anders — Fakultät Physik, TU Dortmund, 44227 Dortmund, Deutschland

We study higher order auto-correlation functions of electron spin decay in an isolated semi-conductor quantum dot described by the central spin model. The electronic central spin is coupled to a bath of nuclear spins via hyperfine interaction, which dominates the short time regime. In a mean field approach the nuclear spin field is assumed to be frozen, since the precession frequency of the electron in the nuclear hyperfine field is much greater than the precession frequency of the nuclei in the hyperfine field of the electron. Since the higher order cumulants of this mean-field approximation vanish, these functions can serve as a tool to reveal the entanglement between the electron spin and the nuclear spin bath. We also evaluate analytically the symmetries exhibited by third order correlation functions in the high-temperature limit. It can be shown that the third order correlation function is constrained to a small subspace of all possible frequencies. Furthermore, we calculate the third order correlation function using the Lanczos-algorithm and statistic trace evaluation. The viability of this method is benchmarked by the analysis of the established spin noise spectrum given by the second order correlation function.