title: Quantum Smoluchowski equation for a spin bath.
abstract: We derive the quantum mechanical description of overdamped Brownian motion of a particle in a spin bath of two-level atoms. The resulting Smoluchowski equation is used to calculate the rate of escape of the particle from a metastable state. At 0 K the decay rate is finite. We show that while quantization enhances the decay rate, higher temperatures induce thermal saturation, resulting in effective a reduction of the system-bath coupling. The role of coherence is examined.
authors: Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
authors: Sudarson Sekhar
authors: SS
authors: Sinha
authors: Arnab
authors: A
authors: Ghosh
authors: Deb Shankar
authors: DS
authors: Ray