Macroscopic amplification of an ultra-small interaction in superfluid 3He

2017 Fiscal Year Final Research Report

• Project/Area Number: 26287084
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Ikegami Hiroki 国立研究開発法人理化学研究所, 創発物性科学研究センター, 専任研究員 (70313161)
• Co-Investigator(Kenkyū-buntansha): 石黒 亮輔 日本女子大学, 理学部, 准教授 (40433312)
• Co-Investigator(Renkei-kenkyūsha): SATO Daisuke 国立研究開発法人理化学研究所, 創発物性科学研究センター, 協力研究員 (00709363)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 超流動ヘリウム３ / 時間反転対称性の破れ / カイラリティ / 巨視的量子現象 / 超低温 / 量子凝縮

Outline of Final Research Achievements

In the A phase of the superfluid 3He, the Cooper pairs can have a very tiny interaction between their orbital angular momentum and an external magnetic field even though 3He-A consists of charge-neutral Cooper pairs. In order to examine this unusual interaction experimentally, we developed a ultra-low temperature cryostat with a high magnetic field and constructed an experimental setup.
We also conducted experimental studies of a 3He film formed of a surface of a 3He-4He mixture liquid. The 3He film should offer an ideal platform for examining the above-mentioned effect because it has a smooth surfaces at both surfaces. To investigate properties of the 3He film, we measured mobility of electrons trapped on the surface of the mixture liquid. We found that the mobility is dominated by reflection of ballistic 3He quasiparticles at the surface. Detailed analysis elucidated that 3He quasiparticles experience unusual reflection at the surface.

Free Research Field

低温物理