arXiv subjects

Andras Vukics

Publications and source records attributed to Andras Vukics.

3 recordsLinked to original sources

arXiv2010

C++QED: a framework for simulating open quantum dynamics

C++QED is a framework for simulating open quantum dynamics in general. Historically, it has in the first place been developed for problems in moving-particle cavity QED, but since then has been applied in other fields as well. It is known to be able to simulate full Master equation up to several thousand, and quantum trajectories up to several hundred thousand dimensions. The basic idea of the framework is to allow users to build arbitrarily complex interacting quantum systems from elementary free subsystems and interactions between them, and simulate their time evolution with a number of available time-evolution drivers. Apart from providing a number of elements out of the box, there are several tools which facilitate the implementation of new elements. These are being added continuously, on demand.

quant-ph↗

arXiv2007

Prospects for the cavity-assisted laser cooling of molecules

Cooling of molecules via free-space dissipative scattering of photons is thought not to be practicable due to the inherently large number of Raman loss channels available to molecules and the prohibitive expense of building multiple repumping laser systems. The use of an optical cavity to enhance coherent Rayleigh scattering into a decaying cavity mode has been suggested as a potential method to mitigate Raman loss, thereby enabling the laser cooling of molecules to ultracold temperatures. We discuss the possibility of cavity-assisted laser cooling particles without closed transitions, identify conditions necessary to achieve efficient cooling, and suggest solutions given experimental constraints. Specifically, it is shown that cooperativities much greater than unity are required for cooling without loss, and that this could be achieved via the superradiant scattering associated with intracavity self-localization of the molecules. Particular emphasis is given to the polar hydroxyl radical (OH), cold samples of which are readily obtained from Stark deceleration.

quant-ph↗

arXiv2005

Entanglement driven self-organization via a quantum seesaw mechanism

Atom-field entanglement is shown to play a crucial role for the onset of spatial self-organization of ultracold atoms in an optical lattice within a high-Q cavity. Like particles on a seesaw, the atoms feel a different potential depending on their spatial distribution. The system possesses two stable configurations, where all atoms occupy either only even or only odd lattice sites. While for a classical cavity field description a distribution balanced between even and odd sites is a stationary equilibrium state at zero temperature, the possibility of atom-field entanglement in a quantum field description yields an instant simultaneous decay of the homogeneous atomic cloud into an entangled superposition of the two stable atomic patterns correlated with different cavity fields. This effect could be generic for a wide class of quantum phase transitions, whenever the quantum state can act back on the control parameter.

quant-ph↗