Related papers: Measuring Spin Accumulations with Current Noise
We describe the construction and operation of a two-channel noise detection system for measuring power and cross spectral densities of current fluctuations near 2 MHz in electronic devices at low temperatures. The system employs cryogenic…
The conventional definition of spin-current, namely spin density multiplied by the group velocity, is not a conserved quantity due to possible spin rotations caused by spin-orbit (SO) interaction. However, in a model with spin-spin…
We present our first experimental determination of the magnetic noise of a superspinglass made of < 1 pico-liter frozen ferrofluid. The measurements were performed with a local magnetic field sensor based on Hall microprobes operated with…
We analyze the noise in a multi-terminal multi-channel conductor under arbitrary time-dependent driving and subject to -- possibly large -- static potential and temperature biases. We show that the full out-of-equilibrium zero-frequency…
We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the…
We develop a theory of spin fluctuations of exciton-polaritons in a semiconductor microcavity under the non-resonant unpolarized pumping. It is shown that the corresponding spin noise is sensitive to the scattering rates in the system,…
We propose nanoscale magnetometry via isolated single-spin qubits as a probe of superconductivity in two-dimensional materials. We characterize the magnetic field noise at the qubit location, arising from current and spin fluctuations in…
Spin fluctuation and transition have always been one of central topics of magnetism and condensed matter science. Experimentally, the spin fluctuation is found transcribed onto scattering intensity in the neutron scattering process, which…
Spin pumping by a moving magnetization gives rise to an electric voltage over a spin valve. Thermal fluctuations of the magnetization manifest themselves as increased thermal voltage noise with absorption lines at the ferromagnetic…
We report a comprehensive study of stochastic electron spin fluctuations -- spin noise -- in lightly doped ($n$-type) bulk GaAs, which are measured using sensitive optical magnetometry based on off-resonant Faraday rotation. Frequency…
Recent measurements in current-driven spin valves demonstrate magnetization fluctuations that deviate from semiclassical predictions. We posit that the origin of this deviation is spin shot noise. On this basis, our theory predicts that…
We theoretically investigate the generation of spin current from a uniformly rotating body with impurity scattering on the basis of the spin dependent transport equation. The spin current is created mainly in the radial direction when a…
We compute the power spectrum of the noise in the current due to spin motive forces by a fluctuating domain wall. We find that the power spectrum of the noise in the current is colored, and depends on the Gilbert damping, the spin transfer…
It is shown that electron-electron interactions lead to a novel quantum-interference contribution to non-equilibrium current noise in mesoscopic conductors. The corresponding noise spectrum is obtained in detail for diffusive systems. It is…
We discuss theoretically a setup where a time-dependent current consisting of a DC bias and two sinusoidal harmonics is driven through a sample. If the sample exhibits current-dependent shot noise, the down-converted noise power spectrum…
Interference of electronic waves undergoing Andreev reflection in diffusive conductors determines the energy profile of the conductance on the scale of the Thouless energy. A similar dependence exists in the current noise, but its behavior…
Using a density matrix formulation for the effective action, we obtain a set of macroscopic equations that describe spin accumulation in a non-homogeneous ferromagnet. We give a new expression for the spin current which extends previous…
We investigate the persistent current in a hybrid Aharonov-Bohm ring - quantum dot system coupled to a reservoir which provides spin fluctuations. It is shown that the spin exchange interaction between the quantum dot and the reservoir…
We present a microscopic theory of spin torque due to diffusive spin currents induced by spin accumulation. The obtained expression is a natural extension of the existing one due to 'local' spin currents associated with ordinary electric…
We develop a theory of spin noise spectroscopy of itinerant, noninteracting, spin-carrying fermions in different regimes of temperature and disorder. We use kinetic equations for the density matrix in spin variables. We find a general…