Speaker             Prof.  X. R. Wang
Affiliation  Physics Department, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China
Short CV
XIANG RONG WANG (王向荣)
EDUCATION: Ph.D. OF PHYSICS, July 1990, University of Rochester, MASTER OF ARTS, May 1986,University of Rochester, BACHELOR OF ARTS, July 1984, Wuhan University, PRC
EXPERIENCE:
    PROFESSOR, 7/09-present, Physics Department, HKUST
    ASSOCIATE PROFESSOR, 1/01-6/09, Physics Department, HKUST
    ASSISTANT PROFESSOR, 8/92-12/00, Physics Department, HKUST
    RESEARCH ASSOCIATE, 9/90-7/92, University of Minnesota
    RESEARCH ASSISTANT, 1/87-8/90, Phys. Dept., U. of Rochester
HONORS:     
    Minnesota Supercomputer Institute Fellow, 1991
    CUSPEA Selectee, China-United States, 1984
RESEARCH FIELD: Condensed Matter Theory and Statistical Physics

TELEPHONE: (852)2358-7488        E-MAIL: phxwan@usthk.ust.hk

Abstract
In this talk, I will present a theory for the recently observed insulating phase of graphene at charge neutrality point in high magnetic field quantum Hall (QH) experiments. We show that the magnetic field driven Peierls-type lattice distortion (due to the Landau level degeneracy) and random bond fluctuations compete with each other, resulting in a transition from a QH-metal state at relative low field to a QH-insulator state at high enough field at the charge neutrality point. The critical field that separates QH-metal from QH-insulator depends on the bond fluctuation. The picture explains well why the field required for observing the insulating phase is lower for a cleaner sample.

时间          2010年9月17日 星期五 下午16:00
地点    四川大学望江校区东区 物理馆 三楼阶梯教室(323室)
四川大学物理科学与技术学院 理论物理研究中心