Intrinsic instability at the Bose-Einstein condensation of bosonic quasiparticles in magnetic insulators

Details Intrinsic instability at the Bose-Einstein condensation of bosonic quasiparticles in magnetic insulators Intrinsic instability at the Bose-Einstein condensation of bosonic quasiparticles in magnetic insulators

2009-08-21

arxiv.org/abs/0908.3033v1

Physics

Condensed Matter

Strongly Correlated Electrons

10 figures, 74 references

Scientific paper

Starting from a phenomenological standard energy functional to describe the condensation of a dilute gas of bosonic quasiparticles in magnetic insulators, we find that the inclusion of a perturbation term that explicitly violates the axial symmetry significantly modifies the details of the resulting Bose Einstein condensation. Systems with an originally axial symmetry must show an intrinsic tendency to spontaneously violate this symmetry as soon as the condensation sets in, and the phase transition at the respective critical field may even become of first order. We can explain a number of features in the experimental data of various insulating spin systems, such as a slightly nonlinear magnetization near the critical field as well as hysteresis effects and peculiarities in the energy-level scheme of TlCuCl3. We also offer a consistent explanation for certain anomalies in the magnetocaloric effect and in the magnetization of BaCuSi2O6 by assuming a spontaneous violation of axial symmetry at the magnetic phase transition on an energy scale of about 1 micro-eV. The resulting anisotropy gap in the magnetic excitation spectrum, that inevitably forms at the critical field of all such systems, lifts the linear Goldstone mode and is therefore seriously limiting the lifetime of magnetic condensates to a few nanoseconds at most.

Affiliated with

Also associated with

No associations

Rating

Intrinsic instability at the Bose-Einstein condensation of bosonic quasiparticles in magnetic insulators 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 Intrinsic instability at the Bose-Einstein condensation of bosonic quasiparticles in magnetic insulators, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intrinsic instability at the Bose-Einstein condensation of bosonic quasiparticles in magnetic insulators will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-666129