Xinlin Song | Searcharxiv

arXiv2015

Resonant and Time-Resolved Spin Noise Spectroscopy

We demonstrate a method to extend the range of pulsed laser spin noise measurements to long spin lifetimes. We use an analog time-domain detection scheme with a bandwidth limited only by laser pulse duration. Our model uses statistics and Bloch-Torrey equations to extract the Lande g-factor, Faraday cross-section $σ_F$, and spin lifetime $τ_S$, while accounting for finite detector response. Varying the magnetic field with a fixed probe-probe delay yields $τ_S$ when it is longer than the laser repetition period. Varying the probe-probe delay with a fixed field produces a time-domain measurement of the correlation function.

cond-mat.mes-hall↗

arXiv2015

Robustness of n-GaAs Carrier Spin Properties to 5 MeV Proton Irradiation

Modern electronic devices utilize charge to transmit and store information. This leaves the information susceptible to external influences, such as radiation, that can introduce short timescale charge fluctuations and, long term, degrade electronic properties. Encoding information as spin polarizations offers an attractive alternative to electronic logic that should be robust to randomly polarized transient radiation effects. As a preliminary step towards radiation-resistant spintronic devices, we measure the spin properties of n-GaAs as a function of radiation fluence using time-resolved Kerr rotation and photoluminescence spectroscopy. Our results show a modest to negligible change in the long-term electron spin properties up to a fluence of 1x10$^{14}$ (5 MeV protons)/cm$^2$, even as the luminescence decreases by two orders of magnitude.

cond-mat.mes-hall↗