arXiv subjects

Rahmatullah

Publications and source records attributed to Rahmatullah.

3 recordsLinked to original sources

arXiv2022

Gain-assisted quantum heat engine based on electromagnetically induced transparency

We present a scheme to realize a gain-assisted quantum heat engine (QHE) based on electromagnetically induced transparency (EIT). The QHE consists of a three-level { \Lambda}-type atomic system that interacts with two thermal reservoirs and a coupling field. The gain without inversion is induced in the system via spontaneously generated coherence (SGC) between two lower levels. The SGC has a significant effect on the system's dynamics, resulting in an enhancement of the emission cross-section and spectral brightness of the QHE.

quant-ph↗

arXiv2017

Understanding of collective atom phase control in modified photon echoes for a near perfect, storage time extended quantum memory

A near perfect, storage time-extended photon echo-based quantum memory protocol has been analyzed by solving the Maxwell-Bloch equations for a backward scheme in a three-level system. The backward photon echo scheme is combined with a controlled coherence conversion process via control Rabi flopping to a third state, where the control Rabi flopping collectively shifts the phase of the ensemble coherence. The propagation direction of photon echoes is coherently determined by the phase matching condition between the data (quantum) and the control (classical) pulses. Herein we discuss the classical controllability of a quantum state for both phase and propagation direction by manipulating the control pulses in both single and double rephasing photon echo schemes of a three-level system. Compared with their well-understood use for two-level photon echoes, the Maxwell-Bloch equations to a three-level system have a critical limitation regarding the phase change when interacted with an arbitrary control pulse area.

quant-ph↗

arXiv2016

Analysis of controlled Rabi flopping in a double rephasing photon echo scheme for quantum memories

A double rephasing photon echo is analyzed for inversion-free photon echo-based quantum memories using controlled Rabi flopping, where the Rabi flopping is used for phase control of atom coherence. Unlike the rephasing-caused pi-phase shift in a single rephasing scheme, the control Rabi flopping between the excited state and an auxiliary third state induces coherence inversion. Thus, the absorptive photon echo in a double rephasing scheme can be manipulated to be emissive via the controlled Rabi flopping. Here we present a quantum coherence control of atom phases in a double rephasing photon echo scheme for emissive photon echoes for quantum memory applications.

quant-ph↗