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Abstracts
P1.8
Universal non-linear I-V at an impurity quantum critical point
Chung Chung-Hou(1), Baranger Harold(2), Lin Chao-Yun(1), Zhang Gu(2), Ke
Chung-Ting(2), and Finkelstein Gleb(2)
1) National Chiao-Tung University, Department of Electrophysics, 1001
University Rd., HsinChu, Taiwan, R.O.C. 300
2)Duke University, Department of Physics, Physics Bldg., Science Dr. Box 90305
Durham, NC 27708 USA
Universal non-linear I-V at an interacting quantum critical point (QCP) is
often out of reach theoretically. Here, however, we provide a striking example of
analytically accessible QCP in a spinless quantum dot coupled to Ohmic resistive
leads through a symmetrical double-barrier, realized in recent experiments. The
transmission approaches unity (on resonance) with a weak backscattering at low
temperature and applied bias when tuned exactly to the QCP. Drawing on the
dynamical Coulomb blockade theory via bosonization and re-fermionization, we
obtain analytically the full I-V curve, in excellent agreement with experiments.
P1.9
Optimized Jastrow correlations for a one dimensional periodic system
Panholzer Martin
Johannes Kepler University, Institute for Theoretical Physics, 4040 Linz
Jastrow correlations are a powerful tool to describe properties of strongly
correlated systems. Mostly these correlations are optimized within variational
Monte Carlo (VMC) calculations, especially for electronic systems. On the
other hand there are diagrammatic methods like Hyper Netted Chain (HNC)
summations, which are very successfully in describing Helium fluids. A drawback,
compared to VMC is the necessary approximation of elementary diagrams. This
is compensated by the lower numerical demand, the parameter free optimization
and the possibility to deal with excited states. The extension of the HNC-method
(and also the Fermion version FHNC) to periodic systems, i.e. a inhomogeneous
density with a certain period, is presented. Special emphasis is given to the
numerical feasibility of the approach. It is shown that by exploiting the symmetry
even realistic three dimensional problems can be treated. The result for a
inhomogeneous but periodic one dimensional electron gas is presented. As
starting point we use a sinusoidal density. With this approach we describe
the transition from a regime where the local density approximation (LDA) is a
good approximation to a regime where it fails. Finally an outlook is given to
possible applications e.g. electrons in solids, Helium adsorbed on surfaces and
metal-Mott insulator transition.
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