arXiv subjects

C. Moritz Carmesin

Publications and source records attributed to C. Moritz Carmesin.

4 recordsLinked to original sources

arXiv2025

Confinement-Induced Resonances in Spherical Shell Traps

The energy spectrum and corresponding wave functions of two bosonic particles confined in a spherically symmetric shell trap and interacting via a three-dimensional zero-range potential are computed. Confinement-induced resonances, originating entirely from the strong coupling of the relative and center-of-mass motions of the two particles, are identified as avoided crossings for certain values of the shell radius. By working close to the found resonances, these results offer a new way to control the atom-atom interaction in an atomic gas by tuning only the geometrical parameters of the shell.

quant-ph↗

arXiv2021

High-gain quantum free-electron laser: long-time dynamics and requirements

We solve the long-time dynamics of a high-gain free-electron laser in the quantum regime. In this regime each electron emits at most one photon on average, independently of the initial field. In contrast, the variance of the photon statistics shows a qualitatively different behavior for different initial states of the field. We find that the realization of a seeded Quantum FEL is more feasible than self-amplified spontaneous emission.

quant-ph↗

arXiv2020

Quantum and classical phase-space dynamics of a free-electron laser

In a quantum mechanical description of the free-electron laser (FEL) the electrons jump on discrete momentum ladders, while they follow continuous trajectories according to the classical description. In order to observe the transition from quantum to classical dynamics, it is not sufficient that many momentum levels are involved. Only if additionally the initial momentum spread of the electron beam is larger than the quantum mechanical recoil, caused by the emission and absorption of photons, the quantum dynamics in phase space resembles the classical one. Beyond these criteria, quantum signatures of averaged quantities like the FEL gain might be washed out.

quant-ph↗

arXiv2019

A high-gain Quantum free-electron laser: emergence & exponential gain

We derive an effective Dicke model in momentum space to describe collective effects in the quantum regime of a free-electron laser (FEL). The resulting exponential gain from a single passage of electrons allows the operation of a Quantum FEL in the high-gain mode and avoids the experimental challenges of an X-ray FEL oscillator. Moreover, we study the intensity fluctuations of the emitted radiation which turn out to be super-Poissonian.

quant-ph↗