9,955 research outputs found
Note on Thermodynamics Method of Black Hole/CFT Correspondence
In the paper we further refine the thermodynamics method of black hole/CFT
correspondence. We show that one can derive the central charges of different
holographic pictures directly from the entropy product if it is
mass-independent, for a black hole in the Einstein gravity or the gravity
without diffeomorphism anomaly. For a general black hole in the Einstein
gravity that admits holographic descriptions, we show that the thermodynamics
method and asymptotic symmetry group (ASG) analysis can always give consistent
results in the extreme limit. Furthermore, we discuss the relation between
black hole thermodynamics and the hidden conformal symmetry. We show that the
condition , with being the outer and inner horizon
areas, is the necessary, but not sufficient, condition for a black hole to have
the hidden conformal symmetry. In particular, for the Einstein(-Maxwell)
gravity is just the condition , with
being the outer and inner horizon entropies, which is the condition for the
entropy product being mass-dependent. When there exists the hidden
conformal symmetry in the low-frequency scattering off the generic non-extremal
black hole, it always leads to the same temperatures of dual CFT as the ones
got from the thermodynamics method.Comment: 31 pages, references added, published versio
The gain and carrier density in semiconductor lasers under steady-state and transient conditions
The carrier distribution functions in a semiconductor crystal in the presence of a strong optical field are obtained. These are used to derive expressions for the gain dependence on the carrier density and on the optical intensity-the gain suppression effect. A general expression for high-order nonlinear gain coefficients is obtained. This formalism is used to describe the carrier and power dynamics in semiconductor lasers above and below threshold in the static and transient regimes
Schwinger boson mean field theory of the Heisenberg Ferrimagnetic Spin Chain
The Schwinger boson mean field theory is applied to the quantum ferrimagnetic
Heisenberg chain. There is a ferrimagnetic long range order in the ground
state. We observe two branches of the low lying excitation and calculate the
spin reduction, the gap of the antiferromagnetic branch, and the spin
fluctuation at . These results agree with the established numerical
results quite well. At finite temperatures, the long range order is destroyed
because of the disappearance of the Bose condensation. The thermodynamic
observables, such as the free energy, magnetic susceptibility, specific heat,
and the spin correlation at , are calculated. The has a
minimum at intermediate temperatures and the spin correlation length behaves as
at low temperatures. These qualitatively agree with the numerical
results and the difference is small at low temperatures.Comment: 15 pages, 5 figures. Accepted by Phys. Rev.
Maximal violation of Clauser-Horne-Shimony-Holt inequality for two qutrits
Bell-Clauser-Horne-Shimony-Holt inequality (in terms of correlation
functions) of two qutrits is studied in detail by employing tritter
measurements. A uniform formula for the maximum value of this inequality for
tritter measurements is obtained. Based on this formula, we show that
non-maximally entangled states violate the Bell-CHSH inequality more strongly
than the maximally entangled one. This result is consistent with what was
obtained by Ac{\'{i}}n {\it et al} [Phys. Rev. A {\bf 65}, 052325 (2002)] using
the Bell-Clauser-Horne inequality (in terms of probabilities).Comment: 6 pages, 3 figure
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