Quantum Condensed Phases Research Team

Principal Investigator

PI Name Kimitoshi Kono
Degree D.Sci.
Title Team Leader
Brief Resume
1982D.Sci., University of Tokyo
1982Research Associate, Hyogo University of Teacher Education
1987Associate Professor, Hyogo University of Teacher Education
1989Associate Professor, Institute of Physics, University of Tsukuba
1992Associate Professor, Institute for Solid State Physics, University of Tokyo
2000Chief Scientist, Low Temperature Physics Laboratory, RIKEN
2013Team Leader, Quantum Condensed Phases Research Team, Quantum Information Electronics Division, RIKEN Center for Emergent Matter Science (-present)


We will develop techniques to manipulate single electrons and ions trapped at an extremely clean surface of liquid helium, which will be utilized to fabricate quantum effect devices. This includes lateral confinement techniques and control of quantum transitions between discrete energy levels due to the abovementioned confinement and due to surface states, and laser spectroscopy of ions (atoms). In addition, superfluidity, a typical emergent phenomenon, will be studied in the context of topological properties associated with a spontaneous symmetry breaking.

Research Fields

Low Temperature Physics


Superfluidity, Surface Phenomena
Two-dimensional electron system
Quantum computing


Novel phenomena in surface charges on liquid helium

Free surface of liquid helium provides a super-clean substrate to support two-dimensional electrons and ions.  Moreover, free surface of superfluid 3He may support Majorana surface bound states, which is closely related with a topological superfluid, and hence, it is an ideal play ground to study the most typical emergent phenomena.

Our team discovered a new transport mode of the electron solid on a capillary condensed He channel.  The electron solid forms a dimple lattice that is commensurate with the electron solid.  This state is a self-trapped state of electron solid by being dressed with surface capillary waves, or ripplons.  Dressing and undressing of ripplon cloud causes a stick-slip motion of the electron solid.

Metallic atoms, ions, and clusters are produced in superfluid helium by laser ablation.  We study quantum many body effects in these objects.  The ablation causes a production of nanoparticles, nanowires, and entangled network of nanowires.  By driving such charged products with strong electric fields, we can study novel electrohydrodynamic phenomena, by employing a high speed camera.

Dendritic structure made of metallic barium formed on the surface of superfluid helium.


Kimitoshi Kono

Team Leader kkono[at]riken.jp R

Petr Moroshkin

Research Scientist

Yu-Chen Sun

Postdoctoral Researcher

Yuichi Okuda

Temporary Employee


Chemistry and Materials Physics Bldg.
2-1 Hirosawa, Wako, Saitama 351-0198 Japan