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101.
We consider the interaction between an f-deformed Bose–Einstein condensate and a single-mode quantized light field. By using the Gardiner’s phonon operators, we find that there exists a natural deformation in the model which modifies the Bogoliubov approximation under the condition of large but finite number of particles in condensate. This approach introduces an intrinsically deformed Bose–Einstein condensate, where the deformation parameter, well-defined by the particle number N in condensate, controls the strength of the associated nonlinearity. By introducing the deformed Gardiner’s phonon operators we modify the very dilute-gas approximation through including atomic collisions in condensate. The rate of atomic collisions κ, as a new deformation parameter in the deformed Bose–Einstein condensate, controls the nonlinearity related to the atomic collisions. We show that by controlling the nonlinearities in the f-deformed atomic condensate through the two atomic parameters N and κ, it is possible to generate and manipulate the nonclassical quantum statistical properties of radiation field, such as, the sub-Poissonian photon statistics and quadrature squeezing. Also, it is possible to control the collapses and revivals phenomena in the average number of photons by atomic parameters N and κ. 相似文献
102.
H. Prakash P. Kumar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):359-363
We study amplitude-squared squeezing of the Hermitian operator Zθ=Z1
cosθ+Z2 sin θ, in the most general superposition state
, of two coherent states
and
. Here operators Z1,2 are defined by
, a is annihilation operator, θ is angle, and
complex numbers C1,2 , α, β are arbitrary and only
restriction on these is the normalization condition of the state
. We define the condition for a state
to be amplitude-squared squeezed for the operator Zθ
if squeezing parameter
, where N=a+a and
. We find
maximum amplitude-squared squeezing of Zθ in the superposed
coherent state
with minimum value 0.3268 of the
parameter S for an infinite combinations with α- β= 2.16
exp [±i(π/4) + iθ/2],
and with
arbitrary values of (α+β) and θ. For this minimum
value of squeezing parameter S, the expectation value of photon number can
vary from the minimum value 1.0481 to infinity. Variations of the parameter
S with different variables at maximum amplitude-squared squeezing are also
discussed. 相似文献
103.
光子消灭算符高次幂本征态的振幅N次方压缩 总被引:4,自引:0,他引:4
本文研究了光子消灭算符高次幂ak(k≥3)的k个正交归一本征态的振幅N次方压缩特性,结果表明,当k为偶数时,这些本征态均可存在振幅N次方(N=(m+1/2)k,m=0,1,2,…)压缩。 相似文献
104.
Nikolai Tyutyulkov Oskar E. Polansky Peter Schuster Stojan karabunarliev Christo I. Ivanov 《Theoretical chemistry accounts》1985,67(3):211-228
Theoretical investigation of the band structure of three types of nonclassical polymers, namely alternant (one- and two-dimensional), nonalternant and heteroatomic, are carried out. Although polyradicals, these polymers have a considerable delocalization energy which may determine their relative stability.The spin-density distribution of the alternant type of non-classical polymers corresponds to a ferrimagnetic ground state at 0 K.The non-classical polymers represent a new class of organic systems as their band structure and magnetic properties essentially differ from those of common polymers. 相似文献
105.
J. Bylander I. Robert-Philip I. Abram 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(2):295-301
Two independent photons, produced through the spontaneous emission of two separate emitters subject to uncorrelated dephasing
processes, can display two-photon interference (i.e. coalescence into a two-photon state) when they are incident simultaneously on a beamsplitter, in a manner analogous to that
of twin photons produced through degenerate parametric fluorescence. The presence of dephasing processes, however, reduces
the interference contrast (i.e. the probability of coalescence), by the ratio of the coherence time to the lifetime of the emitter.
Received 9 September 2002 Published online 17 December 2002
RID="a"
ID="a"e-mail: izo.abram@lpn.cnrs.fr 相似文献
106.
T. Golubeva Yu. Golubev C. Fabre N. Treps 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):179-193
In this paper, we investigate several properties of the
full signal-idler-pump mode quantum state generated by a triply
resonant non-degenerate Optical Parametric Oscillator operating
above threshold, with an injected wave on the signal and idler
modes in order to lock the phase diffusion process. We determine
and discuss the spectral purity of this state, which turns out not
to be always equal to 1 even though the three interacting modes
have been taken into account at the quantum level. We have seen
that the purity is essentially dependent on the weak
intensity of the injected light and on an asymmetry of the
synchronization. We then derive the expression of its total
three-mode Glauber P-function, and calculate the joint
signal-idler photon number probability distribution and
investigate their dependence on the injection. 相似文献
107.
F. C. Lourenço A. Vidiella-Barranco 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(1):127-131
We propose a scheme in which entanglement can be transferred from atoms (discrete variables) to
entangled states of cavity fields (continuous variables). The cavities play the role of a kind of quantum memory for
entanglement, in such a way that it is possible to retrieve it back to the atoms. In our method, two
three level atoms in a lambda configuration, previously entangled, are set to interact with
single mode cavity fields prepared in coherent states. During the process, one e-bit of entanglement may be
deposited in the cavities in an efficient way. We also show that the stored entanglement may be transferred back
to flying atoms. 相似文献
108.
Sintayehu Tesfa 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):351-358
Squeezing properties of a two-mode
radiation produced by a process of driven degenerate parametric
down conversion, when the cavity is coupled to two independent
squeezed vacuum reservoirs employing the linearization procedure,
are analyzed. The two-mode cavity and output radiations exhibit
considerable squeezing even when the oscillator is coupled to a
vacuum reservoir. One of the effects of coupling the cavity to the
squeezed vacuum reservoirs is to increase the degree of squeezing
exponentially. For the output radiation the correlation of the
quadrature operators evaluated at different times also contributes
to the squeezing, which is the reason for quenching of the overall
noise in one of the quadrature components of the fundamental mode. 相似文献
109.
110.
Martin Andreas Robert George Prof. Dr. Otto Dopfer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(44):e202200577
Radical cations of diamondoids, a fundamental class of very stable cyclic hydrocarbon molecules, play an important role in their functionalization reactions and the chemistry of the interstellar medium. Herein, we characterize the structure, energy, and intermolecular interaction of clusters of the amantadine radical cation (Ama+, 1-aminoadamantane) with solvent molecules of different interaction strength by infrared photodissociation (IRPD) spectroscopy of mass-selected Ama+Ln clusters, with L=Ar (n≤3) and L=N2 and H2O (n=1), and dispersion-corrected density functional theory calculations (B3LYP−D3/cc-pVTZ). Three isomers of Ama+ generated by electron ionization are identified by the vibrational properties of their rather different NH2 groups. The ligands bind preferentially to the acidic NH2 protons, and the strength of the NH…L ionic H-bonds are probed by the solvation-induced red-shifts in the NH stretch modes. The three Ama+ isomers include the most abundant canonical cage isomer ( I ) produced by vertical ionization, which is separated by appreciable barriers from two bicyclic distonic iminium ions obtained from cage-opening (primary radical II ) and subsequent 1,2 H-shift (tertiary radical III ), the latter of which is the global minimum on the Ama+ potential energy surface. The effect of solvation on the energetics of the potential energy profile revealed by the calculations is consistent with the observed relative abundance of the three isomers. Comparison to the adamantane cation indicates that substitution of H by the electron-donating NH2 group substantially lowers the barriers for the isomerization reaction. 相似文献