123 research outputs found
Measuring photon-photon interactions via photon detection
The strong non-linearity plays a significant role in physics, particularly,
in designing novel quantum sources of light and matter as well as in quantum
chemistry or quantum biology. In simple systems, the photon-photon interaction
can be determined analytically. However, it becomes challenging to obtain it
for more compex systems. Therefore, we show here how to measure strong
non-linearities via allowing the sample to interact with a weakly pumped
quantized leaking optical mode. We found that the detected mean-photon number
versus pump-field frequency shows several peaks. Interestingly, the interval
between neighbour peaks equals the photon-photon interaction potential.
Furthermore, the system exhibits sub-Poissonian photon statistics, entanglement
and photon switching with less than one photon. Finally, we connect our study
with existing related experiments.Comment: 4 pages, 3 figure
Field-emitter bound states in structured thermal reservoirs
We derive a master equation for a two-level emitter interacting with a band-gap reservoir at finite temperatures. This equation is able to capture effects of emitter-reservoir entanglement. We show that the entangled field-emitter bound state, which arises in the process of interaction, does not survive indefinitely at finite temperatures. However, such an entangled state may be effectively excited through an intensive incoherent driving.75
Asymmetric universal entangling machine
We give a definition of asymmetric universal entangling machine which
entangles a system in an unknown state to a specially prepared ancilla. The
machine produces a fixed state-independent amount of entanglement in exchange
to a fixed degradation of the system state fidelity. We describe explicitly
such a machine for any quantum system having levels and prove its
optimality. We show that a -dimensional ancilla is sufficient for reaching
optimality. The introduced machine is a generalization to a number of widely
investigated universal quantum devices such as the symmetric and asymmetric
quantum cloners, the symmetric quantum entangler, the quantum information
distributor and the universal-NOT gate.Comment: 28 pages, 3 figure
Non-perturbative gluon evolution, squeezing, correlations and chaos in jets
We study evolution of colour gluon states in isolated QCD jet at the
non-perturbative stage. Fluctuations of gluons are less than those for coherent
states under specific conditions. This fact suggests that there gluon squeezed
states can arise. The angular and rapidity dependencies of the normalized
second-order correlation function for present gluon states are studied at this
stage of jet evolution. It is shown that these new gluon states can have both
sub-Poissonian and super-Poissonian statistics corresponding to, respectively,
antibunching and bunching of gluons by analogy with squeezed photon states.
We investigate the possibility of coexisting both squeezing and chaos using
Toda criterion and temporal correlator analysis. It is shown that these effects
may coexist under some conditions.Comment: 18 pages, 3 figures, Reported on IPPP Workshop on Multiparticle
Production in QCD Jets (University of Durham, Durham, UK, 12-15 December
2001
INVERSE SCATTERING TRANSFORM ANALYSIS OF STOKES-ANTI-STOKES STIMULATED RAMAN SCATTERING
Zakharov-Shabat--Ablowitz-Kaup-Newel-Segur representation for
Stokes-anti-Stokes stimulated Raman scattering is proposed. Periodical waves,
solitons and self-similarity solutions are derived. Transient and bright
threshold solitons are discussed.Comment: 16 pages, LaTeX, no figure
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