Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1003.3960

Analysis of Optical Deshelving in Photon Echo-based Quantum Memories

Byoung Seung HAM

Published Mar 21, 2010• 1 citation
arXivHTMLPDF

Abstract

Storage time extension in photon echoes using optical deshelving via a robust spin state has been investigated for absorption-dependent optical leakage, where an incomplete population transfer, even by a πoptical pulse obviates the phase recovery condition of the deshelving. We analyze an optical depth-dependent echo leakage mechanism in the storage time extended photon echoes for the usage of optical deshelving to photon echo-based quantum memories.

DOI
10.48550/arxiv.1003.3960

Related papers

Rephasing halted photon echoes using controlled optical deshelving

Joonseong Hahn, Byoung Seung HAM

Quantum coherence control of two-pulse photon echoes has been demonstrated for a rephasing halt, resulting in storage-time extension using atom phase-controlled optical deshelving (optical locking) in a backward propagation scheme for the additional benefit of echo intensity enhancement. Compared with conventional forward two-pulse photon echoes, the backward two-pulse photon echo efficiency is enhanced by 15-fold even in a dilute sample, and the storage time is lengthened by spin dephasing time accelerated by spin inhomogeneous broadening. The mechanism of delayed photon echoes via optical locking is due to the temporal hold of the rephasing process by coherent population transfer to a robust spin state.

New Journal of Physics•Sep 7, 2011•13 citations

Control of photon storage time using phase locking

Byoung Seung HAM

A photon echo storage-time extension protocol is presented by using a phase locking method in a three-level backward propagation scheme, where phase locking serves as a conditional stopper of the rephasing process in conventional two-pulse photon echoes. The backward propagation scheme solves the critical problems of extremely low retrieval efficiency and pi rephasing pulse-caused spontaneous emission noise in photon echo based quantum memories. The physics of the storage time extension lies in the imminent population transfer from the excited state to an auxiliary spin state by a phase locking control pulse. We numerically demonstrate that the storage time is lengthened by spin dephasing time.

Optics Express•Jan 14, 2010•19 citations

Ultralong photon-echo-based quantum memories using optical locking

Byoung Seung HAM

Unlike slow-light-based quantum memories, photon echoes offer the benefit of high speed and wide bandwidth. Over the last decade, the rephasing mechanism of photon echoes has been studied for quantum memories to overcome fundamental limitations in photon echoes, such as population inversion and low retrieval efficiency. Although these limitations have been overcome in modified photon echo schemes, photon storage time is still too short to apply it to long-distance quantum communications. For long-distance quantum communications, ultralong photon storage time of the order of seconds is needed to implement quantum repeaters. In this review article, challenging techniques for ultralong photon storage are presented, where ultralong storage is obtained via a coherence conversion process between optical and spin states by using an optical locking technique. To remove population-inversion-caused quantum noise, a double rephasing scheme is addressed, where rephasing-pulse-caused population inversion hinders photon echoes for quantum memory applications.

Journal of the Optical Society of America B•Feb 27, 2012•0 citations

Analysis of optical locking applied for rephasing halt in photon echoes

Byoung Seung HAM

Optical locking applied to rephased atoms in photon echoes is analyzed for on-demand photon storage time extension, where the storage time extension is confined by the inverse of spin inhomogeneous broadening. Both optical locking and photon storage mechanisms in atomic frequency comb echoes are discussed and compared with those in two-pulse photon echo-based phase-locked echoes and three-pulse photon echoes.

Journal of the Optical Society of America B•Mar 18, 2011•4 citations

A contradictory phenomenon of deshelving pulses in a dilute medium used for lengthened photon storage time

Byoung Seung HAM

Lengthening of photon storage time has been an important issue in quantum memories for long distance quantum communications utilizing quantum repeaters. Atom population transfer into an auxiliary spin state has been adapted to increase photon storage time of photon echoes. In this population transfer process phase shift to the collective atoms is inevitable, where the phase recovery condition must be multiple of 2pi to satisfy rephasing mechanism. Recent adaptation of the population transfer method to atomic frequency comb (AFC) echoes [Afzelius et al., Phys. Rev. Lett. 104, 040503 (2010)], where the population transfer method is originated in a controlled reversible inhomogeneous broadening technique [Moiseev and Kroll, Phys. Rev. Lett. 87, 173601 (2001)], however, shows contradictory phenomenon violating the phase recovery condition. This contradiction in AFC is reviewed as a general case of optical locking applied to a dilute medium for an optical depth-dependent coherence leakage resulting in partial retrieval efficiency.

Optics Express•Aug 3, 2010•11 citations

Atom phase controlled noise-free photon echoes

Byoung Seung HAM

Rephasing in photon echoes is a fundamental mechanism of retrieving optical information stored in a collective ensemble of atoms or ions. With an extremely weak quantum optical data, population inversion by the rephasing process is inevitable resulting in serious quantum noise. Here, an inversion-free rephasing method in photon echoes is presented by using deshelving-based atom phase control. The present method makes photon echoes directly applicable to quantum memories with benefits of extended photon storage time and nearly perfect retrieval efficiency. In this revised version only the rephasing pulse propagation direction is corrected to make a silent echo of E1 in Fig. 1.

arXiv:1101.5480•Jan 28, 2011•10 citations
Storage time extension in photon echoes using optical deshelving via a robust spin state has been investigated for absorption-dependent optical leakage, where an incomplete population transfer, even by a πoptical pulse obviates the phase recovery condition of the deshelving. We analyze an optical depth-dependent echo leakage mechanism in the storage time extended photon echoes for the usage of optical deshelving to photon echo-based quantum memories.
Quantum coherence control of two-pulse photon echoes has been demonstrated for a rephasing halt, resulting in storage-time extension using atom phase-controlled optical deshelving (optical locking) in a backward propagation scheme for the additional benefit of echo intensity enhancement. Compared with conventional forward two-pulse photon echoes, the backward two-pulse photon echo efficiency is enhanced by 15-fold even in a dilute sample, and the storage time is lengthened by spin dephasing time accelerated by spin inhomogeneous broadening. The mechanism of delayed photon echoes via optical locking is due to the temporal hold of the rephasing process by coherent population transfer to a robust spin state.
A photon echo storage-time extension protocol is presented by using a phase locking method in a three-level backward propagation scheme, where phase locking serves as a conditional stopper of the rephasing process in conventional two-pulse photon echoes. The backward propagation scheme solves the critical problems of extremely low retrieval efficiency and pi rephasing pulse-caused spontaneous emission noise in photon echo based quantum memories. The physics of the storage time extension lies in the imminent population transfer from the excited state to an auxiliary spin state by a phase locking control pulse. We numerically demonstrate that the storage time is lengthened by spin dephasing time.
Unlike slow-light-based quantum memories, photon echoes offer the benefit of high speed and wide bandwidth. Over the last decade, the rephasing mechanism of photon echoes has been studied for quantum memories to overcome fundamental limitations in photon echoes, such as population inversion and low retrieval efficiency. Although these limitations have been overcome in modified photon echo schemes, photon storage time is still too short to apply it to long-distance quantum communications. For long-distance quantum communications, ultralong photon storage time of the order of seconds is needed to implement quantum repeaters. In this review article, challenging techniques for ultralong photon storage are presented, where ultralong storage is obtained via a coherence conversion process between optical and spin states by using an optical locking technique. To remove population-inversion-caused quantum noise, a double rephasing scheme is addressed, where rephasing-pulse-caused population inversion hinders photon echoes for quantum memory applications.
Lengthening of photon storage time has been an important issue in quantum memories for long distance quantum communications utilizing quantum repeaters. Atom population transfer into an auxiliary spin state has been adapted to increase photon storage time of photon echoes. In this population transfer process phase shift to the collective atoms is inevitable, where the phase recovery condition must be multiple of 2pi to satisfy rephasing mechanism. Recent adaptation of the population transfer method to atomic frequency comb (AFC) echoes [Afzelius et al., Phys. Rev. Lett. 104, 040503 (2010)], where the population transfer method is originated in a controlled reversible inhomogeneous broadening technique [Moiseev and Kroll, Phys. Rev. Lett. 87, 173601 (2001)], however, shows contradictory phenomenon violating the phase recovery condition. This contradiction in AFC is reviewed as a general case of optical locking applied to a dilute medium for an optical depth-dependent coherence leakage resulting in partial retrieval efficiency.
Rephasing in photon echoes is a fundamental mechanism of retrieving optical information stored in a collective ensemble of atoms or ions. With an extremely weak quantum optical data, population inversion by the rephasing process is inevitable resulting in serious quantum noise. Here, an inversion-free rephasing method in photon echoes is presented by using deshelving-based atom phase control. The present method makes photon echoes directly applicable to quantum memories with benefits of extended photon storage time and nearly perfect retrieval efficiency. In this revised version only the rephasing pulse propagation direction is corrected to make a silent echo of E1 in Fig. 1.