Clement Wong

Spin-transfer mechanism for magnon-drag thermopower

We point out a relation between the dissipative spin-transfer-torque parameter β and the contribution of magnon drag to the thermoelectric power in conducting ferromagnets. Using this result, we estimate β in iron at low temperatures, where magnon drag is believed to be the dominant contribution to the thermopower. Our results may be used to determine β from magnon-drag-thermopower experiments, or, conversely, to infer the strength of magnon drag via experiments on spin transfer.

Spin-Seebeck effect in a strongly interacting Fermi gas

We study the spin-Seebeck effect in a strongly interacting, two-component Fermi gas and propose an experiment to measure this effect by relatively displacing spin-up and spin-down atomic clouds in a trap using spin-dependent temperature gradients. We compute the spin-Seebeck coefficient and related spin-heat transport coefficients as functions of temperature and interaction strength. We find that, when the interspin scattering length becomes larger than the Fermi wavelength, the spin-Seebeck coefficient changes sign as a function of temperature, and hence so does the direction of the spin separation. We compute this zero-crossing temperature as a function of interaction strength and in particular in the unitary limit for the interspin scattering.

Quantum efficiency of a single microwave photon detector based on a semiconductor double quantum dot

Motivated by recent interest in implementing circuit quantum electrodynamics with semiconducting quantum dots, we consider a double quantum dot (DQD) capacitively coupled to a superconducting resonator that is driven by the microwave field of a superconducting transmission line. We analyze the DQD current response using input-output theory and show that the resonator-coupled DQD is a sensitive microwave single photon detector. Using currently available experimental parameters of DQD-resonator coupling and dissipation, including the effects of

Entanglement of condensed magnons via momentum-space fragmentation

1/f

Spin-heat relaxation and thermospin diffusion in atomic Bose and Fermi gases

charge noise and phonon noise, we determine the parameter regime for which incident photons are completely absorbed and near-unit

Quasiparticle Berry curvature and Chern numbers in spin-orbit-coupled bosonic Mott insulators

\ensuremath{\gtrsim}98

Spin caloritronics in noncondensed Bose gases

% efficiency can be achieved. We show that this regime can be reached by using very high quality resonators with quality factor

Relaxation of atomic polarization in paraffin-coated cesium vapor cells

Q\ensuremath{\simeq}{10}^{5}

Topological transport in spin-orbit coupled bosonic Mott insulators.

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High Fidelity Singlet-Triplet

A scheme is presented for engineering momentum-space entanglement of fragmented magnon condensates. We consider easy plane frustrated antiferromagnets in which the magnon dispersion has degenerate minima that represent umbrella chiral spin textures. With an applied magnetic field, we tune the Hamiltonian near a quantum critical point that is is signaled by a singularity in the entanglement entropy. The ground state develops momentum-space entanglement of the chiral spin textures. The size of the entangled superposition is accessible experimentally through the magnetic structure factor. Our model is motivated by equilibrium magnon condensates in frustrated antiferromagnets such as CsCuCl3, and it can also be simulated in spin-orbit coupled Mott insulators in atomic optical lattices and circuit quantum electrodynamics.