In-Situ Measurement of the Density Ratio of the K-Rb-21Ne Comagnetometer Based on Electron Spin Relaxation Rate

Accurate measurement of alkali metal density ratio in hybrid vapor cells is essential for high sensitivity of comagnetometers. We introduce and investigate a new method of measuring the density ratio based on electron spin-relaxation rate. The Bloch equations including the parameter of density ratio are studied, and the density measurement results show that measurement uncertainty is less than 12%. The advantage of this method is measuring the in-situ density ratio, which is more precise and useful for optimizing sensitivity of comagnetometers by adjusting the density ratio in real time.

Validation of Structural Grounds for Anomalous Molecular Mobility in Ionic Liquid Glasses

Ionic liquid (IL) glasses have recently drawn much interest as unusual media with unique physicochemical properties. In particular, anomalous suppression of molecular mobility in imidazolium IL glasses vs. increasing temperature was evidenced by pulse Electron Paramagnetic Resonance (EPR) spectroscopy. Although such behavior has been proven to originate from dynamics of alkyl chains of IL cations, the role of electron spin relaxation induced by surrounding protons still remains unclear. In this work we synthesized two deuterated imidazolium-based ILs to reduce electron–nuclear couplings between radical probe and alkyl chains of IL, and investigated molecular mobility in these glasses. The obtained trends were found closely similar for deuterated and protonated analogs, thus excluding the relaxation-induced artifacts and reliably demonstrating structural grounds of the observed anomalies in heterogeneous IL glasses.

Impacts of Crystal Quality on Carrier Recombination and Spin Dynamics in (110)-Oriented GaAs/AlGaAs Multiple Quantum Wells at Room Temperature

We have systematically investigated the structural properties, carrier lifetimes, namely, photoluminescence (PL) lifetimes (τPL), and electron spin relaxation times (τs) in (110) GaAs/AlGaAs multiple quantum wells (MQWs) by using time-resolved PL measurements. The MQWs were grown by molecular beam epitaxy within a wide range of the growth temperature Tg (430–600 °C) and a high V/III flux ratio using As2. At 530 °C < Tg < 580 °C, we found that the quality of the heterointerfaces is significantly improved, resulting in τPL~40 ns at RT, one order of magnitude longer than those reported so far. Long τs (~6 ns) is also observed at RT.