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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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