已为您找到该学者18条结果 成果回收站
【期刊论文】Topological Gauge Structure and Phase Diagram of a Doped Antiferromagnet
寇谡鹏, Su-Peng Kou and Zheng-Yu Weng
,-0001,():
-1年11月30日
We show that a topological gauge structure in an e ective description of the t-J model gives rise to a global phase diagram of antiferromagnetic (AF) and superconducting (SC) phases in a weakly doped regime. Dual confinement and deconfinement of holons and spinons play essential roles here, with a quantum critical point at a doping concentration xc≃0.043. The complex experimental phase diagram at low doping is well described within such a framework.
-
9浏览
-
0点赞
-
0收藏
-
0分享
-
45下载
-
0
-
引用
【期刊论文】Crossover from thermal hopping to quantum tunneling in Mn12Ac
寇谡鹏, S. P. Kou, , J. Q. Liang, Y.B. Zhang., X.B.Wang and F. C. Pu
,-0001,():
-1年11月30日
The crossover from thermal hopping to quantum tunneling is studied. We show that the decay rate-with dissipation can accurately be determined near the crossover temperature. Besides considering the Wentzel-Kramers-Brillouin (WKB) 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 can't be calculated by the steepest descent method and show that higher order couplings between the two dangerous modes need to be taken into considerations. At last the crossover from thermal hopping to quantum tunneling in the molecular agnet Mn12Ac is studied.
-
46浏览
-
0点赞
-
0收藏
-
0分享
-
49下载
-
0
-
引用
【期刊论文】Macroscopic quantum coherence in mesoscopic ferromagnetic systems
寇谡鹏, S. P. Kou, , J. Q. Liang, Y.B. Zhang. and F. C. Pu
,-0001,():
-1年11月30日
In this paper we study the Macroscopic Quantum Oscillation (MQO) e ect in ferromagnetic single domain magnets with a magnetic field applied along the hard anistropy axis. The level splitting for the ground state, derived with the conventional instanton method, oscillates with the external field and is quenched at some field values. A formula for quantum tunneling at excited levels is also obtained. The existence of topological phase accounts for this kind of oscillation and the corresponding thermodynamical quantities exhibit similar interference e ects which resembles to some extent the electron quantum phase interference induced by gauge potential in the Aharonov- Bohm effect and the-vacuum in Yang-Mills field theory.
-
30浏览
-
0点赞
-
0收藏
-
0分享
-
49下载
-
0
-
引用