39 research outputs found
Lowest Weight Representations, Singular Vectors and Invariant Equations for a Class of Conformal Galilei Algebras
The conformal Galilei algebra (CGA) is a non-semisimple Lie algebra labelled
by two parameters and . The aim of the present work is to investigate
the lowest weight representations of CGA with for any integer value of
. First we focus on the reducibility of the Verma modules. We give a
formula for the Shapovalov determinant and it follows that the Verma module is
irreducible if and the lowest weight is nonvanishing. We prove that
the Verma modules contain many singular vectors, i.e., they are reducible when
. Using the singular vectors, hierarchies of partial differential
equations defined on the group manifold are derived. The differential equations
are invariant under the kinematical transformation generated by CGA. Finally we
construct irreducible lowest weight modules obtained from the reducible Verma
modules
Enhanced quantum phase synchronization of a laser-driven qubit under non-Markovian dynamics
In this paper, we demonstrate transient dynamics of Husimi Q-representation
to visualize and characterize the phase synchronization behavior of a two-level
system (qubit) driven by a laser field in both the Markov and non-Markov
regime. In the Markov regime, phase preference of the qubit goes away in the
long time limit, whereas the long-time phase localization persists in the
non-Markovian regime. We also plot the maximum of the shifted phase
distribution in two different ways: (a) by varying the detuning and laser drive
strength, and (b) by varying the system-bath coupling and laser drive strength.
Signature of quantum phase synchronization viz. the Arnold tongue is
demonstrated through the maximal value of the shifted phase distribution. The
phase synchronization is observed inside the tongue region while the region
outside the tongue is desynchronized. The synchronization regions are
determined by various system-environment parameters and the qubit phase
synchronization is shown to be enhanced in the non-Markov regime.Comment: 6 figure