212 research outputs found
Ground-state properties of one-dimensional anyon gases
We investigate the ground state of the one-dimensional interacting anyonic
system based on the exact Bethe ansatz solution for arbitrary coupling constant
() and statistics parameter (). It
is shown that the density of state in quasi-momentum space and the ground
state energy are determined by the renormalized coupling constant . The
effect induced by the statistics parameter exhibits in the momentum
distribution in two aspects: Besides the effect of renormalized coupling, the
anyonic statistics results in the nonsymmetric momentum distribution when the
statistics parameter deviates from 0 (Bose statistics) and
(Fermi statistics) for any coupling constant . The momentum distribution
evolves from a Bose distribution to a Fermi one as varies from 0 to
. The asymmetric momentum distribution comes from the contribution of the
imaginary part of the non-diagonal element of reduced density matrix, which is
an odd function of . The peak at positive momentum will shift to
negative momentum if is negative.Comment: 6 pages, 5 figures, published version in Phys. Rev.
Particle partitioning entanglement in itinerant many-particle systems
For itinerant fermionic and bosonic systems, we study `particle
entanglement', defined as the entanglement between two subsets of particles
making up the system. We formulate the general structure of particle
entanglement in many-fermion ground states, analogous to the `area law' for the
more usually studied entanglement between spatial regions. Basic properties of
particle entanglement are uncovered by considering relatively simple itinerant
models.Comment: 4 pages, 4 figure
SO2 oxidation in supercooled droplets in the presence of O2
Sulphur dioxide oxidation in supercooled monodisperse droplets at T4213 7C was studied in the presence of oxygen. The SO2 concentration was found to range from 0.08 to 7.1 ppmv and the contact time between gases and droplets was
210 s. The experimental results showed that sulphate concentration due to SO2 oxidation is independent of temperature, i.e. the increase of SO2 solubility in the
liquid phase balances the rate constant decrease of the oxidation reaction. Following McKayâs kinetics (Atmos. Environ., 5 (1971) 7), we calculated the rate constant at
T4213 7C and the activation energy. A comparison was made between experimental S(VI) oxidation concentrations due to oxygen and theoretical oxidation values due to O3, H2O2 and oxygen in the presence of catalyzers (Fe31, Mn21)
Finite-size effects in roughness distribution scaling
We study numerically finite-size corrections in scaling relations for
roughness distributions of various interface growth models. The most common
relation, which considers the average roughness . This illustrates how
finite-size corrections can be obtained from roughness distributions scaling.
However, we discard the usual interpretation that the intrinsic width is a
consequence of high surface steps by analyzing data of restricted
solid-on-solid models with various maximal height differences between
neighboring columns. We also observe that large finite-size corrections in the
roughness distributions are usually accompanied by huge corrections in height
distributions and average local slopes, as well as in estimates of scaling
exponents. The molecular-beam epitaxy model of Das Sarma and Tamborenea in 1+1
dimensions is a case example in which none of the proposed scaling relations
works properly, while the other measured quantities do not converge to the
expected asymptotic values. Thus, although roughness distributions are clearly
better than other quantities to determine the universality class of a growing
system, it is not the final solution for this task.Comment: 25 pages, including 9 figures and 1 tabl
Correlation amplitude and entanglement entropy in random spin chains
Using strong-disorder renormalization group, numerical exact diagonalization,
and quantum Monte Carlo methods, we revisit the random antiferromagnetic XXZ
spin-1/2 chain focusing on the long-length and ground-state behavior of the
average time-independent spin-spin correlation function C(l)=\upsilon
l^{-\eta}. In addition to the well-known universal (disorder-independent)
power-law exponent \eta=2, we find interesting universal features displayed by
the prefactor \upsilon=\upsilon_o/3, if l is odd, and \upsilon=\upsilon_e/3,
otherwise. Although \upsilon_o and \upsilon_e are nonuniversal (disorder
dependent) and distinct in magnitude, the combination \upsilon_o + \upsilon_e =
-1/4 is universal if C is computed along the symmetric (longitudinal) axis. The
origin of the nonuniversalities of the prefactors is discussed in the
renormalization-group framework where a solvable toy model is considered.
Moreover, we relate the average correlation function with the average
entanglement entropy, whose amplitude has been recently shown to be universal.
The nonuniversalities of the prefactors are shown to contribute only to surface
terms of the entropy. Finally, we discuss the experimental relevance of our
results by computing the structure factor whose scaling properties,
interestingly, depend on the correlation prefactors.Comment: v1: 16 pages, 15 figures; v2: 17 pages, improved discussions and
statistics, references added, published versio
Critical interfaces and duality in the Ashkin Teller model
We report on the numerical measures on different spin interfaces and FK
cluster boundaries in the Askhin-Teller (AT) model. For a general point on the
AT critical line, we find that the fractal dimension of a generic spin cluster
interface can take one of four different possible values. In particular we
found spin interfaces whose fractal dimension is d_f=3/2 all along the critical
line. Further, the fractal dimension of the boundaries of FK clusters were
found to satisfy all along the AT critical line a duality relation with the
fractal dimension of their outer boundaries. This result provides a clear
numerical evidence that such duality, which is well known in the case of the
O(n) model, exists in a extended CFT.Comment: 5 pages, 4 figure
Entanglement entropy and multifractality at localization transitions
The von Neumann entanglement entropy is a useful measure to characterize a
quantum phase transition. We investigate the non-analyticity of this entropy at
disorder-dominated quantum phase transitions in non-interacting electronic
systems. At these critical points, the von Neumann entropy is determined by the
single particle wave function intensity which exhibits complex scale invariant
fluctuations. We find that the concept of multifractality is naturally suited
for studying von Neumann entropy of the critical wave functions. Our numerical
simulations of the three dimensional Anderson localization transition and the
integer quantum Hall plateau transition show that the entanglement at these
transitions is well described using multifractal analysis.Comment: v3, 5 pages, published versio
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