SCIENCE SPIN-OFFS

[dockzef]

Indirect Methods to Control Population Distribution in a Large Spin System

Lingfei Zhao, Maxim Goryachev, Jeremy Bourhill, Michael E. Tobar
(Submitted on 3 Nov 2016)

We demonstrate how a large spin system
(S=7/2)
with the ground and the first excited state separated by a seven photon transition exhibit non equilibrium thermodynamic properties and how the population distribution may be manipulated using coupling between energy levels. The first method involves non-adiabatic passage through an avoided level crossing controlled with an external DC magnetic field and the resulting Landau Zener transition. The second method is based on external cavity pumping to a higher energy state hybridised with another state that is two single photon transitions away from the ground state. The results are confirmed experimentally with Gd

3+
impurity ion ensemble in a YVO

4
crystal cooled to 20 mK, which also acts as a photonic whispering gallery mode resonator. Extremely long life times are observed due to large number of photons required for the transition between the ground and the first excited states.

https://arxiv.org/abs/1611.00874