题　目：Current-induced Atomic Dynamics and Heat Transport in Molecular Conductors
报告人：吕京涛 教授 （丹麦工业大学）
时　间：6月27日（周三），上午11：00-12：00
地　点：物理馆512会议室

摘要：
We describe a semi-classical Langevin equation obtained from path-integrals to study the atomic dynamics of a molecular junction in the presence of electrical current. The electronic environment serves as an effective non-equilibrium bath. The bath results in random forces describing Joule heating, and deterministic current-induced forces. We make several predictions based on the theory: (1) The current-induced forces are generally not conservative. They also include a geometric magnetic part; [1,2,3] (2) By engeering the electronic levels of a molecular rectifier, phonon amplification by stimulated emission (phaser) is possible;[4] (3) It is possible to pump heat between two isothermal phonon baths using the electrical current. All these effects are closely related to the breaking time-reversal symmetry induced by the electrical current.

[1] D. Dundas, E. J. McEniry, T. N. Todorov, Nat. Nanotechnol., 4, 99 (2009).
[2] J. T. Lü, Mads Brandbyge and Per Hedegård, Nano Letters, 10, 1657 (2010).
[3] J. T. Lü, Mads Brandbyge Per Hedegård, T. N. Todorov and D. Dundas, Phys. Rev. B, in press.
[4] J. T. Lü, Per Hedegård and Mads Brandbyge, Phys. Rev. Lett., 107, 046801 (2011).

个人简介：
2001年本科毕业于清华大学材料科学与工程系；
2001-2006年在中科院上海微系统攻读博士学位，从事太赫兹量子级联激光器中的电子输运性质的研究；
2006-2008年在新加坡国立大学物理系；
2008-2010年在丹麦工业大学微纳米技术系从事纳米结构中电子和热输运方面的研究；
2010年起担任丹麦工业大学微纳米技术系助理教授。