Influence of an external magnetic field on the decoherence of a central spin coupled to an antiferromagnetic environment
arXiv:0706.0934 · doi:10.1088/1367-2630/9/7/219
Abstract
Using the spin wave approximation, we study the decoherence dynamics of a central spin coupled to an antiferromagnetic environment under the application of an external global magnetic field. The external magnetic field affects the decoherence process through its effect on the antiferromagnetic environment. It is shown explicitly that the decoherence factor which displays a Gaussian decay with time depends on the strength of the external magnetic field and the crystal anisotropy field in the antiferromagnetic environment. When the values of the external magnetic field is increased to the critical field point at which the spin-flop transition (a first-order quantum phase transition) happens in the antiferromagnetic environment, the decoherence of the central spin reaches its highest point. This result is consistent with several recent quantum phase transition witness studies. The influences of the environmental temperature on the decoherence behavior of the central spin are also investigated.
29 preprint pages, 4 figures, to appear in New Journal of Physics
References in corpus (10)
- Experimental quantum teleportation
- Non-Markovian dynamics in a spin star system: Exact solution and approximation techniques
- Mixed-state fidelity and quantum criticality at finite temperature
- Decoherence induced by interacting quantum spin baths
- Electron spin phase relaxation of phosphorus donors in nuclear spin enriched silicon
- Non-Markovian reduced dynamics and entanglement evolution of two coupled spins in a quantum spin environment
- Universal decoherence induced by an environmental quantum phase transition
- Exact quantum jump approach to open systems in Bosonic and spin baths
- Frustration of Decoherence in Open Quantum Systems
- Dissipative quantum oscillator with two competing heat baths