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Abstracts
O2.6
Mobility of Electrons on
3
He-
4
He Mixture
Ikegami Hiroki(1), Sato Daisuke(1), Kim Kitak(2), Choi Hyoungsoon(2), and
Kono Kimitoshi(1)
1) The Center for Emergent Matter Science, RIKEN, Wako, Saitama 351-0198,
Japan
2) Department of Physics, KAIST, Daejeon 305-701, Republic of Korea
Adsorbed
3
He atoms on a free surface of
3
He-
4
He mixture liquid offer an ideal
two-dimensional (2D) Fermi system with a tunable interaction between
3
He,
showing 2D Fermi degeneracy and potentially superfluidity. To study properties of
the 2D
3
He, we performed a first systematic measurement of mobility of electrons
trapped on the free surface down to 10 mK by varying the concentration of
3
He
from 0.5 to 6.1 %. We found that the mobility in the Wigner crystal regime is
understood in terms of the viscosity of the bulk liquid at temperatures higher
than about 100 mK and the specular reflection of ballistic
3
He quasiparticles
below 100 mK. We discuss the influence of the 2D
3
He on the mobility.
O2.7
Stick-slip motion of a single electron chain on the surface of liquid
helium
Rees David(1,2), Beysengulov Niyaz (2,3), Lin Juhn-Jong(1,2), Kono Kimitoshi
(1,2,3)
1) National Chiao Tung University, Institute of Physics, NCTU-RIKEN Joint
Research Laboratory, Hsinchu 300, Taiwan
2) RIKEN CEMS, Wako 351-0198, Japan
3) Kazan Federal University, Institute of Physics, KFU-RIKEN Joint Research
Laboratory, Kazan 420008, Russia
A quasi-1D electron crystal moving across the surface of liquid helium performs
stick-slip motion (SSM) due to repeated coupling and decoupling with surface
capillary waves (ripplons)[1]. The decoupling threshold force is larger when the
electrons form well-defined rows, due to the enhancement of resonant ripplon
scattering. Here we show that continuously reducing the number of electrons in
the crystal therefore results in a modulation of the SSM as the number of rows
changes. We find that the SSM persists even in the limit of the single electron
chain. The influence of reduced dimensionality on the electron-ripplon coupling
will be discussed.
[1] D. G. Rees et al., PRL 116 (2016).
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