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Bo-Sture K Skagerstam

Publications and source records attributed to Bo-Sture K Skagerstam.

6 recordsLinked to original sources

On Collective Effects in Cavity Quantum Electrodynamics

We investigate the role of collective effects in the micromaser system as used in various studies of the physics of cavity electrodynamics. We focus our attention on the effect on large-time correlations due to multi-atom interactions. The influence of detection efficiencies and collective effects on the appearance of trapping states at low temperatures is also found to be of particular importance.

quant-ph↗

Macroscopic Interference Effects in Resonant Cavities

We investigate the possibility of interference effects induced by macroscopic quantum-mechanical superpositions of almost othogonal coherent states - a Schroedinger cats state - in a resonant microcavity. Despite the fact that a single atom, used as a probe of the cat state, on the average only change the mean number of photons by one unit, we show that this single atom can change the system drastically. Interference between the initial and almost orthogonal macroscopic quantum states of the radiation field can now take place. Dissipation under current experimental conditions is taken into account and it is found that this does not necessarily change the intereference effects dramatically.

quant-ph↗

Theory of the Microscopic Maser Phase Transitions

Phase diagrams of the micromaser system are mapped out in terms of the physical parameters at hand like the atom cavity transit time, the atom-photon frequency detuning, the number of thermal photons and the probability for a pump atom to be in its excited state. Critical fluctuations are studied in terms of correlation measurements on atoms having passed through the micromaser or on the microcavity photons themselves. At sufficiently large values of the detuning we find a ``twinkling'' mode of the micromaser system. Detailed properties of the trapping states are also presented.

quant-ph↗

On the Phases Structure of the Micromaser System

We investigate, in an exact manner, the phase structure of the micromaser system in terms of the physical parameters at hand like the atom cavity transit time, the atom-photon frequency detuning, the number of thermal photons and the probability for a pump atom to be in its excited state. Phase diagrams are mapped out for various values of the physical parameters. At sufficiently large values of the detuning, we find a ``twinkling'' mode of the micromaser system. A correlation length is used to study fluctuations close to the various phase transitions.

quant-ph↗

Localization of Massless Spinning Particles and the Berry Phase

The components of the position operator, at a fixed time, for a massless and spinning particle with given helicity $λ$ described in terms of bosonic degrees of freedom have an anomalous commutator proportional to $λ$. The position operator generates translations in momentum space. We show that a ray-representation for these translations emerges due to the non-commuting components of the position operators and relate this to the Berry-phase for photons. The Tomita-Chiao experiment then gives support for this relativistic and quantum mechanical description of photons in terms of non-commuting position operators.

hep-th↗