7 papers · 1 filter
Spin bath-mediated decoherence in superconductors
Nikolay Prokof'ev, Philip Stamp
We consider a SQUID tunneling between 2 nearly degenerate flux states. Decoherence caused by paramagnetic and nuclear spins in the low- limit is shown to be much stronger than t…
Quantum Relaxation of Ensembles of Nanomagnets
N. V. Prokof'ev, P. C. E. Stamp
Recent theory and experiment in crystals of molecular magnets suggest that fundamental tests of the decoherence mechanisms of macroscopic quantum phenomena may be feasible in these…
Short Time Quantum AC response of a system of Nanomagnets
G. Rose, P. C. E. Stamp
We calculate the magnetisation relaxation in the short-time regime for an ensemble of nanomagnets in the presence of a low-frequency external AC biasing field, at temperatures lowe…
Effects of Phonons and Nuclear Spins on the Tunneling of a Domain Wall
M. Dube, P. C. E. Stamp
We consider the quantum dynamics of a magnetic domain wall at low temperatures, where dissipative couplings to magnons and electrons are very small. The wall motion is then determi…
A pair of interacting spins coupled to an environmental sea: dissipation and mutual decoherence
M. Dube, P. C. E. Stamp
We consider the quantum dynamics of two spin-1/2 systems, each coupled to a bath of oscillators, so that a bath-mediated coupling is generated between the spins. We find that the i…
Quantum Coherence in Magnetic Grains
N. V. Prokof'ev, P. C. E. Stamp
We consider a model of the dynamics of a magnetic grain, incorporating interactions with nuclear and paramagnetic spins, conduction electrons, and phonons. Decoherence comes both f…