INTRODUCTION OF LABORATORY

What happens when materials are cooled down close to absolute zero temperature? It sounds a boring question because everything freezes at T = 0. It is NOT, however, in some materials because quantum fluctuations persist even at absolute zero temperature. It was first discovered by Heike Kamerlingh Onnes at 1911, who was the first to liquify Helium and reach ~ 1 K, that the resistance of mercury suddenly vanished at low temperature. Followed by the discovery of the superconducting transition, many amazing quantum phenomena - superfluid transition of Helium, Bose-Einstein condensations of Alkali Bose gases - were found at low temperatures. We are interested in these quantum condensed states at low temperatures where the thermal fluctuation is negligible. Especially, we are now focusing on studies to characterize the elementary excitations of a new quantum condensed state of spins which may emerge in frustrated magnetic materials, such as antiferromagnets at two-dimensional triangular or kagome lattices, by precise themo-dynamic measurements at ultra-low temperatures.

MINORU YAMASHITA LAB. research

 

Our home-built ultralow temperature cryostat which allows us to perform various measurements down to ultralow temperatures (1 mK) under a strong magnetic field (13 T).

MINORU YAMASHITA LAB. research

 

Temperature dependence of the thermal Hall conductivity observed in kagome antiferromagnet Cd-kapellasite. Although this material is a blue transparent insulator, the trajectory of the thermal current is bent under the magnetic field.

Message

EXPLORING SOMETHING UNKNOWN IS ALWAYS EXCITING. JOIN OUR CHALLENGES FOR MYSTERIES HIDING IN NEW MATERIALS UNDER UNPRECEDENTED EXTREME ENVIRONMENTS.

We are studying exotic phenomena at very low temperatures. Helium, for example, never freezes but remains liquid even at absolute zero temperature. Liquid Helium undergoes a superfluid transition at ~2 K and shows bizarre phenomena below the transition temperature - a flow without viscosity, a creeping climbing along container walls, etc. These phenomena are well known examples of macroscopic manifestations of the quantum mechanics which describes phenomena at microscopic length scales. Macroscopic quantum states provide us clear cuts to understand quantum physics which often defies our intuitive understandings of Nature. Condensed-matter physics at very low temperatures are good playgrounds to study these macroscopic quantum phenomena, and are our main research fields. In particular, when a trivial stable state is frustrated by quantum fluctuations, new non-trivial states emerge. We are now exploring these exotic states of new materials down to very low temperatures.

PROFILE

Associate Professor Minoru Yamashita

Associate Professor Minoru Yamashita

2000-2005 Department of Physics, Graduate School of Science, Kyoto University, Ph.D. Science

2005-2007 JSPS Research Fellow (PD), ISSP, University of Tokyo and Cornell University

2007-2007 Postdoctoral Associate, Cornell University (J.C. Davis group)

2007-2012 Assistant Professor, Department of Physics, Kyoto University (Matsuda-Shibauchi group)

2012-2013 Research Scientist, Riken (Kato group)

2013-present Associate Professor, Institute for Solid State Physics, The University of Tokyo

STUDENT VOICE

Kousei Iso

Kousei Iso

Prof. Yamashita is bright and gentle person. He always gives me good advices based on his wealth of knowledge and experience to perform my measurements at ultralow temperatures. He is the best person for students like me who want to be a master of ultralow-temperature physics. In Yamashita laboratory, a variety of advanced and unique measurements, including my ultralow-temperature measurements, are possible to study the physical properties of various metals and insulators. We enjoy our graduate student’s life with all members.


Visiting laboratory

  • +81-4-7136-3350
  • Minoru Yamashita Lab.,
  • Department Of Advanced Materials Science,
  • Graduate School of Frontier Sciences,
  • The University of Tokyo
  • Kashiwanoha 5-1-5,
  • Kashiwa,Chiba 277-8561, Japan
  • my@issp.u-tokyo.ac.jp