ﻻ يوجد ملخص باللغة العربية
The spin chemical potential characterizes the tendency of spins to diffuse. Probing the spin chemical potential could provide insight into materials such as magnetic insulators and spin liquids and aid optimization of spintronic devices. Here, we introduce single-spin magnetometry as a generic platform for non-perturbative, nanoscale characterization of spin chemical potentials. We use this platform to investigate magnons in a magnetic insulator, surprisingly finding that the magnon chemical potential can be efficiently controlled by driving the systems ferromagnetic resonance. We introduce a symmetry-based two-fluid theory describing the underlying magnon processes, realize the first experimental determination of the local thermomagnonic torque, and illustrate the detection sensitivity using electrically controlled spin injection. Our results open the way for nanoscale control and imaging of spin transport in mesoscopic spin systems.
Many proposed experiments involving topological insulators (TIs) require spatial control over time-reversal symmetry and chemical potential. We demonstrate reconfigurable micron-scale optical control of both magnetization (which breaks time-reversal
We develop a linear-response transport theory of diffusive spin and heat transport by magnons in magnetic insulators with metallic contacts. The magnons are described by a position dependent temperature and chemical potential that are governed by dif
We report that Bi$_2$Se$_3$ thin films can be epitaxially grown on SrTiO$_{3}$ substrates, which allow for very large tunablity in carrier density with a back-gate. The observed low field magnetoconductivity due to weak anti-localization (WAL) has a
We observe an unusual behavior of the spin Hall magnetoresistance (SMR) measured in a Pt ultra-thin film deposited on a ferromagnetic insulator, which is a tensile-strained LaCoO3 (LCO) thin film with the Curie temperature Tc=85K. The SMR displays a
The interaction energy for the indirect-exchange or Ruderman-Kittel-Kasuva-Yosida (RKKY) interaction between magnetic spins localized on lattice sites of the $alpha$-${cal T}_3$ model is calculated using linear response theory. In this model, the $te