Optical spectroscopy of quantum spin systems

M. Grüninger, Marco Windt, E. Benckiser +4 more

Tigran V. Shahbazyan, I. E. Perakis, M. É. Raǐkh

Valerii S Zapasskii, A. Greilich, Scott A. Crooker +6 more

Spontaneous fluctuations of the magnetization of a spin system in thermodynamic equilibrium (spin noise) manifest themselves as noise in the Faraday rotation of probe light. We show that the correlation properties of this noise over the optical spectrum can provide clear information about the composition of the spin system that is largely inaccessible for conventional linear optics. Such optical spectroscopy of spin noise, e.g., allows us to clearly distinguish between optical transitions associated with different spin subsystems, to resolve optical transitions that are unresolvable in the usual optical spectra, to unambiguously distinguish between homogeneously and inhomogeneously broadened optical bands, and to evaluate the degree of inhomogeneous broadening. These new possibilities are illustrated by theoretical calculations and by experiments on paramagnets with different degrees of inhomogeneous broadening of optical transitions [atomic vapors of 41K and singly charged (In,Ga)As quantum dots].

G. Caimi

Valerii S Zapasskii, G. G. Kozlov, I. I. Ryzhov

The effect of magnetic resonance in the Faraday-rotation noise, demonstrated for the first time on an atom system more than 40 years ago, laid the foundations of a new research direction, the spin noise spectroscopy, that has been developing extensively in the last 20 years. Currently, the most popular research objects are atom and semiconductor paramagnetic materials, while research subjects are the magnetic resonance spectroscopy, the spin dynamics, the optical spectroscopy, the spectroscopy of light polarization noises. The rapid development of this new research direction laying at the interface between optics and radio spectroscopy continuously extends the field of its applicability and opens new opportunities to use it in the experimental physics. In this article we present a few episodes that are important stages in the spin noise spectroscopy development in the last years. The article was prepared as a report on the XV Russian Conference on the Physics of Semiconductors. Keywords: spin noise spectroscopy, magnetic resonance, optical anisotropy, inhomogeneous broadening.

Jacob Smith, Crystal Senko, Phil Richerme +3 more