When: 9:00 a.m., Friday, June 17, 2016

Where: Room 140, Building No. 32, Peiyang Park Campus

Topic 1: Surface State Electrons on liquid helium surface

Lecturer: Kimitoshi Kono, Team Leader, Quantum Condensed Phases Research, RIKEN CEMS

About the Lecturer: Dr. Kono received his BS degree from University of Tokyo in 1977 and his PhD degree from University of Tokyo in 1982. He was the vice-president of IUPAP (The International Union of Pure and Applied Physics) from 2011 to 2014. Now he is the team leader of Quantum Condensed Phases Research, RIKEN CEMS. His research interests focus on: 1) Quantum Fluids and Solids, in particular, surface phenomena of normal and superfluid 4He, 3He, and their mixtures. 2) Experimental investigations on these systems have been carried out by using surface state electrons and ions trapped under the free surfaces. Dr. Kono has published about 70 research papers in his field, and 21 of them were published in Phys. Rev. Lett., 2 in Science, and 1 in Nature.

About the Lecture: Electrons slowly approaching from outside to liquid helium surface cannot enter liquid He because of large negative electron affinity of He atoms. Rather, they form a weak bound state in the vicinity of surface by the action of image charges of individual electrons in front of the surface, the image charge which is analogous to one induced at the metal surface, but the magnitude is very much smaller. The surface state electrons on liquid helium is known to form the Wigner solid, a pure electron lattice. In this seminar, we report about peculiar transport properties of the Wigner solid on a liquid He surface. In addition, the investigation of superfluid helium-3 surface by means of surface state electrons and ions may be briefly mentioned.

Topic 2: The Kondo Effect – from Spin to Orbital Degrees of Freedom

Lecturer: Juhn-Jong Lin, NCTU–RIKEN Joint Research Laboratory, Institute of Physics National Chiao Tung University (Taiwan)

About the Lecturer: Professor Juhn-Jong Lin received his BS degree from National Chiao Tung University (NCTU) in 1979, and his PhD degree from Purdue University (USA) in 1986. He was an associate professor and a professor in the Department of Physics at National Taiwan University from 1988 to 1997. He joined the Institute of Physics of NCTU in 1997. His research efforts focus on low temperature physics, mesoscopic physics, nanoscale physics, and disordered electronic systems. Website: http://web.it.nctu.edu.tw/~jjlin/

About the Lecture: The Kondo effect is a long-standing paradigmatic many-body problem in condensed matter physics. The recent progresses in nanoscience and technology has further made possible new realizations of exotic Kondo physics. In this talk, I will discuss some experimental aspects of (1) the standard Kondo effect due to the existence of isolated localized spin-half magnetic moments, and (2) the two-impurity Kondo effect featured quantum critical behaviors of the transport properties. (3) I will briefly discuss our observation of nonmagnetic Kondo effect due to two-level tunneling systems. In this case, the Kondo physics originates from the coupling of the electronic orbital wavefunctions with dynamical structural defects.

Organizer: Department of Physics at the School of Science

All students and staff of Tianjin University are welcome.