科研之友
微信
新浪微博
Facebook
分享链接
摘要
We consider a three-dimensional quantum antiferromagnet in the vicinity of a quantum critical point separating the magnetically ordered and the magnetically disordered phases. A specific example is TlCuCl(3) where the quantum phase transition can be driven by hydrostatic pressure and/or by external magnetic field. As expected, two transverse and one longitudinal magnetic excitations have been observed in the pressure-driven magnetically ordered phase. According to the experimental data, the longitudinal magnon has a substantial width, which has not been understood and has remained a puzzle. In the present work, we explain the mechanism for the width, calculate the width and relate the value of the width with the parameters of the Bose condensate of magnons observed in the same compound. The method of an effective quantum field theory is employed in the work.
- 出版日期2011-10-14
