Spin noise explores local magnetic fields in a semiconductor

Abstract

Rapid development of spin noise spectroscopy of the last decade has led to a number of remarkable achievements in the fields of both magnetic resonance and optical spectroscopy. In this report, we demonstrate a new – magnetometric – potential of the spin noise spectroscopy and use it to study magnetic fields acting upon electron spin-system of an n-GaAs layer in a high-Q microcavity probed by elliptically polarized light. Along with the external magnetic field, applied to the sample, the spin noise spectrum revealed the Overhauser field created by optically oriented nuclei and an additional, previously unobserved, field arising in the presence of circularly polarized light. This “optical field” is directed along the light propagation axis, with its sign determined by sign of the light helicity. We show that this field results from the optical Stark effect in the field of the elliptically polarized light. This conclusion is supported by theoretical estimates.

Spin-alignment noise in atomic vapor

“…During the last years, this technique has revealed a number of unique capabilities [6][7][8][9]. Specifically, the SNS made it possible to observe resonant magnetic susceptibility of nanosystem (quantum wells, quantum dots), inaccessible for the conventional EPR spectroscopy [10,11], to examine magnetization dynamics of nuclei [12,13] and to investigate nonlinear phenomena in such systems [14][15][16][17]. The SNS technique also allows one to distinguish between homogeneously and inhomogeneously broadened lines of optical transitions [18,19] or to measure homogeneous linewidth in an inhomogeneously broadened system using multiprobe noise technique [20]; intensity modulation of the probe beam made it possible to expand the frequency range of signals detected in SNS up to microwave frequencies [21,22].…”

Spin inertia and polarization recovery in quantum dots: Role of pumping strength and resonant spin amplification

“…This is equivalent to an additional longitudinal magnetic field acting only during the pump pulse. The spin rotation is caused by the effective additional longitudinal magnetic field appearing due to the dynamic Zeeman effect, which suppresses the role of nuclear fluctations [30,31]. The dynamic Zeeman effect results from the optical Stark effect in the field of the circularly polarized light.…”

Subsecond nuclear spin dynamics in n -GaAs

“…[4]) has considerably progressed during recent years [5][6][7][8][9]. The application of modern optical techniques like Faraday rotation [10,11], spin noise [12,13] and time-resolved photoluminescence [6,7], combined with more traditional techniques of magneto-optical spectroscopy and nuclear magnetic resonance (NMR) [14,15], gave the opportunity to identify the basic mechanisms of spin and energy relaxation in the intertwined spin systems of nuclei and resident charge carriers [16].…”