arXiv subjects

A. V. Papoyan

Publications and source records attributed to A. V. Papoyan.

3 recordsLinked to original sources

arXiv2020

Inverse square root level-crossing quantum two-state model

We introduce a new unconditionally solvable level-crossing two-state model given by a constant-amplitude optical field configuration for which the detuning is an inverse-square-root function of time. This is a member of one of the five families of bi-confluent Heun models. We prove that this is the only non-classical exactly solvable field configuration among the bi-confluent Heun classes, solvable in terms of finite sums of the Hermite functions. The general solution of the two-state problem for this model is written in terms of four Hermite functions of a shifted and scaled argument (each of the two fundamental solutions presents an irreducible combination of two Hermite functions). We present the general solution, rewrite it in terms of more familiar physical quantities and analyze the time dynamics of a quantum system subject to excitation by a laser field of this configuration.

quant-ph↗

arXiv2007

Implementation of a double-scanning technique for studies of the Hanle effect in Rubidium vapor

We have studied the resonance fluorescence of a room-temperature rubidium vapor exited to the atomic 5P3/2 state (D2 line) by powerful single-frequency cw laser radiation (1.25 W/cm^2) in the presence of a magnetic field. In these studies, the slow, linear scanning of the laser frequency across the hyperfine transitions of the D2 line is combined with a fast linear scanning of the applied magnetic field, which allows us to record frequency-dependent Hanle resonances from all the groups of hyperfine transitions including V- and Lambda - type systems. Rate equations were used to simulate fluorescence signals for 85Rb due to circularly polarized exciting laser radiation with different mean frequency values and laser intensity values. The simulation show a dependance of the fluorescence on the magnetic field. The Doppler effect was taken into account by averaging the calculated signals over different velocity groups. Theoretical calculations give a width of the signal peak in good agreement with experiment.

physics.atom-ph↗

arXiv2002

A new Manifestation of Atomic Parity Violation in Cesium: a Chiral Optical Gain induced by linearly polarized 6S-7S Excitation

We have detected, by using stimulated emission, an Atomic Parity Violation (APV) in the form of a chiral optical gain of a cesium vapor on the 7S - 6P$_{3/2}$ transition,consecutive to linearly polarized 6S-7S excitation. We demonstrate the validity of this detection method of APV, by presenting a 9% accurate measurement of expected sign and magnitude. We underline several advantages of this entirely new approach in which the cylindrical symmetry of the set-up can be fully exploited. Future measurements at the percent level will provide an important cross-check of an existing more precise result obtained by a different method.

physics.atom-ph↗