QFS 2016 Book of Abstracts

Abstracts

P4.8 Development of Low Temperature Amplifier and Small RF-Coil: Search for New Phase of 3 He in Very Confined Geometry Obara(1), Hirata(1), Okazaki(1), Yano(1), Ishikawa(1), Kashiwaya(2), Koyanagi(2), Kashiwaya(2) 1) Department of Physics, Osaka City University, JAPAN 2) AIST Although 3 He in very confined geometry have been attracted the academic interests for decads, the experimental evidence of the new phases in such geometry are not very clear because of the experimental difficulties. We will show the possibile breakthrough technique to detect the very small NMR signals from the 3 He nuclear-spins in such a confined geometry. Our amplifier consists of three-stage ePHEMT devices, which have the high-gain, high-input-impedance and the low output impedance in several MHz range at 4 K. We are also developing the microfabricated RF-coil so as to detect the NMR signals from thin-thread-shaped sample. We will show and discuss the basic properties of our system. P4.9 Direct spectroscopic study of bubbles containing electrons in excited states: a feasibility study Pal Anustuv, Morrill Drew, Ghosh Ambarish 1) Indian Institute of Science, Dr. A Ghosh, Dept. of Physics, Bangalore, India 2) Brown University, Dept. of Physics, Rhode Island, USA 3) Indian Institute of Science, Dept. of CeNSE, Bangalore, India An electron injected into liquid helium self assembles into a nanometre sized cavity, called the electron bubble. The electron can exist in various energy states, which can be investigated through direct optical absorption. This has been experimentally observed by exciting the electron from the ground (1s) state to excited states by several groups in the past. Here, we present a feasibility study of probing the excited state bubbles with direct optical absorption, which in principle can provide valuable insight into this interesting system. In particular, we propose using a high power laser to drive the ground state bubbles to the excited (1p) state and subsequently measure direct infrared absorption of the 1p bubbles. We will discuss the experimental design, in particular the challenges in detecting such small effects.

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