Inchworm Monte Carlo
is a novel method that effectively suppress dynamical sign problem in real-time evolution
of quantum many-body problems. It iteratively reuse information obtained in previous
Monte Carlo steps.
For various problems it seem to be capable to reach times of a magnitude longer than
other real-time Monte Carlo methods.
Moreover, it is usable as an
impurity solver in DMFT calculations.
paper by P. Hänggi et al
Boltzmann vs Gibbs
or: Is the negative absolute temperature achievable within a standard thermodynamical framework?
The heated debate on the correct definition of entropy is going on.
Authors present a defence of the Boltzmann entropy as a reaction on several
recent papers including the
paper by P. Hänggi et al
The Weyl fermions played
a hide and seek game for over 80 years, but we finally got them.
They must got awfully tired of hiding because now the are everywhere.
The Weyl fermions have been seen in photonic crystals [1]
and, worryingly, they seem to be very interested in Arsenic
[2][3][4].
On the virtues and dangers of partial diagrammatic summation
is a paper by Jan Gukelberger, Li Huang and Philipp Werner where they have compared several approximate diagrammatic schemes with the
quantum Monte Carlo results for 2D Hubbard model in weak coupling regime.
They have shown that the second order perturbation expansion is more reliable than
DMFT,
FLEX, GW and even their combinations.
This attracted my attention not only because it is an important piece of information but also because we have a similar experience
with the study of quantum dot connected to the superconducting leads.
We have seen that the second order perturbation expansion overpowered more elaborated approaches.
A rotten-egg classical superconductor with a critical temperature around -70C!
Who would not be excited.
Nevertheless, let us firstly wait for the confirmation from other groups.