Periodic Instanton and Phase Transition in Quantum Tunneling of Spin Systems

Details Periodic Instanton and Phase Transition in Quantum Tunneling of Spin Systems Periodic Instanton and Phase Transition in Quantum Tunneling of Spin Systems

1999-01-28

arxiv.org/abs/cond-mat/9901325v2

Phys. Lett. A 253, 345(1999)

Physics

Condensed Matter

Soft Condensed Matter

14 pages, revtex, 5 postscript figures

Scientific paper

10.1016/S0375-9601(99)00044-4

The quantum-classical transitions of the escape rates in a uniaxial spin model relevant to the molecular magnet Mn$_{12}$Ac and a biaxial anisotropic ferromagnetic particle are investigated by applying the periodic instanton method. The effective free energies are expanded around the top of the potential barrier in analogy to Landau theory of phase transitions. We show that the first-order transitions occur below the critical external magnetic field $h_x = 1/4$ for the uniaxial spin model and beyond the critical anisotropy constant ratio $\lambda = 1/2$ for the biaxial ferromagnetic grains, which are in good agreement with earlier works.

Affiliated with

Also associated with

No associations

Rating

Periodic Instanton and Phase Transition in Quantum Tunneling of Spin Systems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Periodic Instanton and Phase Transition in Quantum Tunneling of Spin Systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Periodic Instanton and Phase Transition in Quantum Tunneling of Spin Systems will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-598795