1,616 research outputs found
Exact solutions to the time-dependent supersymmetric muliphoton Jaynes-Cummings model and the Chiao-Wu model
By using both the Lewis-Riesenfeld invariant theory and the invariant-related
unitary transformation formulation, the present paper obtains the exact
solutions to the time-dependent supersymmetric two-level multiphoton
Jaynes-Cummings model and the Chiao-Wu model that describes the propagation of
a photon inside the optical fiber. On the basis of the fact that the two-level
multiphoton Jaynes-Cummings model possesses the supersymmetric structure, an
invariant is constructed in terms of the supersymmetric generators by working
in the sub-Hilbert-space corresponding to a particular eigenvalue of the
conserved supersymmetric generators (i.e., the time-independent invariant). By
constructing the effective Hamiltonian that describes the interaction of the
photon with the medium of the optical fiber, it is further verified that the
particular solution to the Schr\"{o}dinger equation is the eigenfunction of the
second-quantized momentum operator of photons field. This, therefore, means
that the explicit expression (rather than the hidden form that involves the
chronological product) for the time-evolution operator of wave function is
obtained by means of the invariant theories.Comment: 14 pages, Latex. This is a revised version of the published paper:
Shen J Q, Zhu H Y 2003 Ann. Phys.(Leipzig) Vol.12 p.131-14
A unified approach to exact solutions of time-dependent Lie-algebraic quantum systems
By using the Lewis-Riesenfeld theory and the invariant-related unitary
transformation formulation, the exact solutions of the {\it time-dependent}
Schr\"{o}dinger equations which govern the various Lie-algebraic quantum
systems in atomic physics, quantum optics, nuclear physics and laser physics
are obtained. It is shown that the {\it explicit} solutions may also be
obtained by working in a sub-Hilbert-space corresponding to a particular
eigenvalue of the conserved generator ({\it i. e.}, the {\it time-independent}
invariant) for some quantum systems without quasi-algebraic structures. The
global and topological properties of geometric phases and their adiabatic limit
in time-dependent quantum systems/models are briefly discussed.Comment: 11 pages, Latex. accepted by Euro. Phys. J.
Gravitomagnetic Field and Time-Dependent Spin-Rotation Coupling
The Kerr metric of spherically symmetric gravitational field is analyzed
through the coordinate transformation from the rotating frame to fixing frame,
and consequently that the inertial force field (with the exception of the
centrifugal force field) in the rotating system is one part of its
gravitomagnetic field is verified. We investigate the spin-rotation coupling
and, by making use of Lewis-Riesenfeld invariant theory, we obtain exact
solutions of the Schr\"{o}dinger equation of a spinning particle in a
time-dependent rotating reference frame. A potential application of these exact
solutions to the investigation of Earths rotating frequency fluctuation
by means of neutron-gravity interferometry experiment is briefly discussed in
the present paper.Comment: 6 pages, 0 figures, Late
Precision measurement of charge number with optomechanically induced transparency
We propose a potentially practical scheme to precisely measure the charge
numbers of small charged objects by optomechanical systems using
optomechanically induced transparency (OMIT). In contrast to the conventional
measurements based on the noise backaction on the optomechanical systems, our
scheme makes use of the small deformation of the mechanical resonator sensitive
to the charge number of the nearby charged object, which could achieve the
detection of a single charge. The relationship between the charge number and
the window width of the OMIT is investigated and the feasibility of the scheme
is justified by numerical simulation using currently available experimental
values.Comment: 6 pages,4 figure
Tunable Frequency Comb Generation from a Microring with a Thermal Heater
We demonstrate a novel comb tuning method for microresonator-based Kerr comb
generators. Continuously tunable, low-noise, and coherent comb generation is
achieved in a CMOS-compatible silicon nitride microring resonator.Comment: submitted to CLEO201
Thickness dependence of superconductivity and superconductor-insulator transition in ultrathin FeSe films on SrTiO3(001) substrate
Interface-enhanced high-temperature superconductivity in one unit-cell (UC)
FeSe film on SrTiO3(001) (STO) substrate has recently attracted much attention
in condensed matter physics and material science. Here, by ex situ transport
measurements, we report on the superconductivity in FeSe ultra-thin films with
different thickness on STO substrate. We find that the onset superconducting
transition temperature (Tc) decreases with increasing film thickness of FeSe,
which is opposite to the behavior usually observed in traditional
superconductor films. By systematic post-annealing of 5 UC FeSe films, we
observe an insulator to superconductor transition, which is accompanied with a
sign change of the dominated charge carriers from holes to electrons at low
temperatures according to the corresponding Hall measurement
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