Educational Activities

Graduate School: Advanced Materials Science

Research Activities

The discovery of new phenomena is at the forefront of research in condensed matter physics. This is particularly true for the inorganic materials, which provide an important basis in current electronic and information technology research, which keep providing numbers of macroscopic quantum phenomena due to correlations among the Avogadro numbers of electrons. Thus, the search for new materials that exhibit new characteristics is one of the most exciting and important projects in the materials research. We have synthesized new materials in so-called strongly correlated electron systems including transition metal compounds and heavy fermion intermetallic compounds. Our interest lies in quantum phenomena such as novel metallic and superconducting states close to spin and orbital orders and quantum spin phenomena in magnetic semiconductors.



A two-dimensional magnetic semiconductor NiGa2S4 developed in our group (Ref. 2)
(Top left) Strongly two-dimensional crystal structure (Top Right) Hexagonal-shaped single crystal
(Bottom) Temperature dependence of the magnetic specific heat. In addition to the conventional peak at the Weiss temperature of 80 K, the unusual peak at T* = 10 K indicates the formation of a novel spin frozen state at low temperatures.

Literature

1) Metallic Spin-Liquid Behavior of the Geometrically Frustrated Kondo Lattice Pr2Ir2O7,
S. Nakatsuji, Y. Machida, Y. Maeno, T. Tayama, T. Sakakibara, J. van Duijn, L. Balicas, J. N. Millican, R. T. Macaluso, and Julia Y. Chan,
Physcial Review Letters Vol.96, 087204 (2006).
2) Spin Disorder on a Triangular Lattice, Satoru Nakatsuji, Yusuke Nambu, Hiroshi Tonomura, Osamu Sakai, Seth Jonas, Collin Broholm, Hirokazu Tsunetsugu, Yiming Qiu, and Yoshiteru Maeno, Science Vol. 309, 1697 (2005).
3) Two Fluid Description of the Kondo Lattice, S. Nakatsuji, D. Pines, and Z. Fisk, Physcial Review Letters Vol. 92, 016401 (2004).
4) Intersite Coupling Effects in a Kondo Lattice, S. Nakatsuji, S. Yeo, L. Balicas, Z. Fisk, P. Schlottmann, P.G. Pagliuso, N.O. Moreno, J.L. Sarrao, and J.D. Thompson, Physical Review Letters Vol.89, 106402 (2002).

Other Activities

Physical Society of Japan

Future Plan

One of our primary interests is the search for new materials that exhibit new quantum phenomena. In our group, we will synthesize new materials in so-called strongly correlated electron systems including transition metal compounds and heavy fermion intermetallic compounds. We will study, (1) low-temperature electronic and magnetic properties of the new transition metal compounds, (2) quantum spin states in two-dimensional magnetic semiconductors, (3) superconductivity, metallic spin liquid states and quantum critical phenomena in heavy fermion systems.

Messages to Students

New materials research often leads to the discovery of new phenomena. By learning the techniques of both synthesis and low temperature measurements, you may discover your own material and be filled with surprise. Through our weekly seminars, in which we learn about the techniques employed at the forefront of condensed matter physics, you will gain the necessary insights to understand novel physics principles, which can then be clarified by your own experiments. I believe that this will be one of the experiences that you will come to treasure in your life.

URL

https://www.nakatsuji-lab.phys.s.u-tokyo.ac.jp/research-topic1?lang=en