5 research outputs found
Exposure of the Hidden Anti-Ferromagnetism in Paramagnetic CdSe:Mn Nanocrystals
We present theoretical and experimental investigations of the magnetism of
paramagnetic semiconductor CdSe:Mn nanocrystals and propose an efficient
approach to the exposure and analysis of the underlying anti-ferromagnetic
interactions between magnetic ions therein. A key advance made here is the
build-up of an analysis method with the exploitation of group theory technique
that allows us to distinguish the anti-ferromagnetic interactions between
aggregative Mn2+ ions from the overall pronounced paramagnetism of magnetic ion
doped semiconductor nanocrystals. By using the method, we clearly reveal and
identify the signatures of anti-ferromagnetism from the measured temperature
dependent magnetisms, and furthermore determine the average number of Mn2+ ions
and the fraction of aggregative ones in the measured CdSe:Mn nanocrystals.Comment: 26 pages, 5 figure
On Holographic Dual of the Dyonic Reissner-Nordstr\"om Black Hole
It is shown that the hidden conformal symmetry, namely symmetry, of the non-extremal dyonic
Reissner-Nordstr\"om black hole can be probed by a charged massless scalar
field at low frequencies. The existence of such hidden conformal symmetry
suggests that the field theory holographically dual to the 4D
Reissner-Nordstr\"om black hole indeed should be a 2D CFT. Although the
associated AdS structure does not explicitly appear in the near horizon
geometry, the primary parameters of the dual CFT can be exactly obtained
without the necessity of embedding the 4D Reissner-Nordstr\"om black hole into
5D spacetime. The duality is further supported by comparing the absorption
cross sections and real-time correlators obtained from both the CFT and the
gravity sides.Comment: 18 pages, no figure, typos correcte
Twofold Hidden Conformal Symmetries of the Kerr-Newman Black Hole
In this paper, we suggest that there are two different individual 2D CFTs
holographically dual to the Kerr-Newman black hole, coming from the
corresponding two possible limits --- the Kerr/CFT and Reissner-Nordstr\"om/CFT
correspondences, namely there exist the Kerr-Newman/CFTs dualities. A probe
scalar field at low frequencies turns out can exhibit two different 2D
conformal symmetries (named by - and -pictures, respectively) in its
equation of motion when the associated parameters are suitably specified. These
twofold dualities are supported by the matchings of entropies, absorption cross
sections and real time correlators computed from both the gravity and the CFT
sides. Our results lead to a fascinating "microscopic no hair conjecture" ---
for each macroscopic hair parameter, in additional to the mass of a black hole
in the Einstein-Maxwell theory, there should exist an associated holographic
CFT description.Comment: 21 pages, 1 figure, typos correcte
The RN/CFT Correspondence Revisited
We reconsidered the quantum gravity description of the near horizon extremal
Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS/CFT
correspondence. We found that, for pure electric case, the right moving central
charge of dual 1D CFT is which is different from the previous result of left moving sector obtained by warped AdS/CFT description. We
discussed the discrepancy in these two approaches and examined novel properties
of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include
Holographic Duals of Near-extremal Reissner-Nordstrom Black Holes
We consider the description of
Reissner-Nordstr{\o}m black holes by studying their uplifted counterparts in
five dimensions. Assuming a natural size of the extra dimension, the near
horizon geometries for the extremal limit are exactly . We compute the scattering amplitude of a scalar field, with a
mode near threshold of frequency and extra dimensional momentum, by a near
extremal uplifted black hole. The absorption cross section agrees with the two
point function of the CFT dual to the scalar field.Comment: reference added, improper statements corrected, 17 pages, no figure