4,621 research outputs found
Stochastic Wave-Function Simulation of Irreversible Emission Processes for Open Quantum Systems in a Non-Markovian Environment
When conducting the numerical simulation of quantum transport, the main
obstacle is a rapid growth of the dimension of entangled Hilbert subspace. The
Quantum Monte Carlo simulation techniques, while being capable of treating the
problems of high dimension, are hindered by the so-called "sign problem". In
the quantum transport, we have fundamental asymmetry between the processes of
emission and absorption of environment excitations: the emitted excitations are
rapidly and irreversibly scattered away. Whereas only a small part of these
excitations is absorbed back by the open subsystem, thus exercising the
non-Markovian self-action of the subsystem onto itself. We were able to devise
a method for the exact simulation of the dominant quantum emission processes,
while taking into account the small backaction effects in an approximate
self-consistent way. Such an approach allows us to efficiently conduct
simulations of real-time dynamics of small quantum subsystems immersed in
non-Markovian bath for large times, reaching the quasistationary regime. As an
example we calculate the spatial quench dynamics of Kondo cloud for a bozonized
Kodno impurity model.Comment: 7 pages, 3 figures, ICQT2017 Conference Proceedings; corrected a few
typos; accepted for publication in the AIP Conference Proceedings journa
Confinement in N=1 SQCD: One Step Beyond Seiberg's Duality
We consider N=1 supersymmetric quantum chromodynamics (SQCD) with the gauge
group U(N_c) and N_c+N quark flavors. N_c flavors are massless; the
corresponding squark fields develop (small) vacuum expectation values (VEVs) on
the Higgs branch. Extra N flavors are endowed with small (and equal) mass
terms. We study this theory through its Seiberg's dual: U(N) gauge theory with
N_c +N flavors of "dual quark" fields plus a gauge-singlet mesonic field M. The
original theory is referred to as "quark theory" while the dual one is termed
"monopole theory." The suggested mild deformation of Seiberg's procedure
changes the dynamical regime of the monopole theory from infrared free to
asymptotically free at large distances. We show that, upon condensation of the
"dual quarks," the dual theory supports non-Abelian flux tubes (strings).
Seiberg's duality is extended beyond purely massless states to include light
states on both sides. Being interpreted in terms of the quark theory, the
monopole-theory flux tubes are supposed to carry chromoelectric fields. The
string junctions -- confined monopole-theory monopoles -- can be viewed as
"constituent quarks" of the original quark theory. We interpret closed strings
as glueballs of the original quark theory. Moreover, there are string
configurations formed by two junctions connected by a pair of different
non-Abelian strings. These can be considered as constituent quark mesons of the
quark theory.Comment: 30 pages, 3 figures; v2 a reference added, minor comments added;
final version to be published in PR
Five-dimensional Monopole Equation with Hedge-Hog Ansatz and Abel's Differential Equation
We review the generalized monopole in the five-dimensional Euclidean space. A
numerical solution with the Hedge-Hog ansatz is studied. The Bogomol'nyi
equation becomes a second order autonomous non-linear differential equation.
The equation can be translated into the Abel's differential equation of the
second kind and is an algebraic differential equation.Comment: 4 pages, 4 figures, typos correcte
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