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Abstracts
P1.25
The ground state phase diagram of 2D spin-pseudospin system
Yu.D. Panov, A.S. Moskvin, A.A. Chikov, K.S. Budrin
Ural Federal University, 620083, Mira str., 19, Ekaterinburg, Russia
High-Tc cuprates show examples of the mutual coexistence and competition of
the spin and charge ordering. We examine the 2D model system where one of the
on-site copper valence triplet states (“pseudospin” S=1 states), or Cu2+, has a
spin s=1/2 degree of freedom. Depending on the value of the on-site correlation,
inter-site density-density interaction, the spin exchange integral and doping, the
system shows different types of the ground state ordering. These include both the
competition and coexistence of the spin and pseudo-spin ordering, for a strong
and weak exchange coupling, respectively. We present the results of the analytical
and numerical calculations.
P1.26
Nonlinear transport of the inhomogeneous Wigner crystal in a channel
geometry
A. V. Smorodin(1), A. O. Badrutdinov(1), D. G. Rees(2), J. Y. Lin(1) and D.
Konstantinov(1).
1) Quantum Dynamics Unit, Okinawa Institute of Science and Technology,
Tancha 1919-1, Okinawa 904-0495, Japan
2) RIKEN-NCTU Joint Laboratory, National Chiao Tung University, 1001 Ta
Hsueh Road, Hsinchu 300, Taiwan
Transport properties of an electronic Wigner crystal on the surface of helium-4
are investigated in a 10 and 5-
µ
m-wide channel, which allows creating a
controllable Wigner crystal inhomogeneity above a variety size of the gate
area. This inhomogeneity significantly affects the Wigner-crystal-attributed
transport phenomena, such as Bragg-Cherenkov scattering and sliding transition.
In particular, when the density above the gate is much higher than in the rest of
the channel, the density-altered area starts behaving as an ”individual” Wigner
crystal, which is revealed in observation of two subsequent sliding transitions. A
simple model is proposed, which allows qualitative explanation of such behavior.
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