CROSSOVER FROM THERMAL HOPPING TO QUANTUM TUNNELING IN FERROMAGNETIC PARTICLE
Kou Su-peng (寇谡鹏)ab, Liang Jiu-qing (梁九卿)ab, Zhang Yun-bo (张云波)ab, Wang Xiao-bing (王小兵)c, Pu Fu-ke (蒲富恪)ad
a Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; b Department of Physics, Shanxi University, Shanxi 030006, China; c Center for Advanced Study, Tsinghua University, Beijing 100084, China; d Department of Physics, Guangzhou Normal College, Guangzhou 510400, China
Abstract The crossover from thermal hopping to quantum tunneling is studied. We show that the decay rate $\varGamma$ with dissipation can accurately be determined near the crossover temperature. Besides considering the Wentzel-Kramers-Brillo uin exponent, we also calculate contribution of the fluctuation modes around the saddle point and give an extended account of a previous study of crossover region. We deal with two dangerous fluctuation modes whose contribution cannot be calculated by the steepest descent method and show that higher order couplings between the two dangerous modes need to be taken into consideration.
Received: 03 November 1998
Accepted manuscript online:
A new modulated structure in α-Fe2O3 nanowires Cai Rong-Sheng (蔡鎔声), Shang Lei (商蕾), Liu Xue-Hua (刘雪华), Wang Yi-Qian (王乙潜), Yuan Lu (袁露), Zhou Guang-Wen (周光文). Chin. Phys. B, 2013, 22(10): 107401.
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
