Rare-earth-doped materials for applications in quantum information storage and signal processing

https://doi.org/10.1016/j.jlumin.2010.12.015Get rights and content

Abstract

Realization of practical quantum memory and optical signal processing systems critically depends on suitable materials that offer specific combinations of properties. Solid-state materials such as rare-earth ions doped into dielectric crystals are one of the most promising candidates for several quantum information storage protocols, including quantum storage of single photons. This article provides an overview of rare-earth-doped material properties and summarizes some of the most promising materials studied in our laboratory and by other groups for applications in quantum information storage and for ultra-wide bandwidth signal processing. Understanding and controlling spectral diffusion in these materials, which ultimately limits the achievable performance of any quantum memory system, is also briefly reviewed. Applications in quantum information impose stringent requirements on laser phase and frequency stability, and employing a narrow spectral hole in the inhomogeneous absorption profile in these materials as a frequency reference can dramatically improve laser stability. We review our work on laser frequency and phase stabilization and report our recent results on using a narrow spectral hole as a passive dynamic spectral filter for laser phase noise suppression, which can dramatically narrow the laser linewidth with or without the requirement of active feedback.

Research highlights

► Rare-earth materials offer key properties for quantum memory and signal processing. ► Physics and properties of rare-earth optical transitions in solids are reviewed. ► Details of 47 promising optical transitions are tabulated and compared. ► A new narrow-band dynamic filtering method using spectral hole burning is discussed. ► Results of successful passive laser phase noise suppression are presented.

Section snippets

Importance of rare-earth-doped materials for quantum information applications

Manipulating coherent quantum superposition states of atoms using light holds enormous potential for future information technology. Quantum information applications offer unprecedented computational capacities via quantum computing, unconditional communication security via quantum cryptography, and reversibly and efficiently mapping the quantum information in a light field to the quantum state of a material [1], [2], [3], [4], [5]. The development of quantum information systems critically

Overview of rare-earth material properties

The rare-earth ions, or lanthanides, form a special group of transition elements in the periodic table. Triply-ionized rare-earth ions have a partially filled 4f shell, shielded from the environment by the outer filled 5s2 and 5p6 electron shells. The partially filled 4fN shell gives rise to narrow spectral lines due to inner shell 4f–4f transitions that span the far infrared to the vacuum ultraviolet. Even when doped into a crystalline host, the shielding of the 4fN levels causes the crystal

Survey of rare-earth-doped materials

Extensive studies of rare-earth materials with long coherence lifetimes have been reviewed by Macfarlane and Shelby [49], Macfarlane [38], [50], Sun [31], and Sun et al. [51]. Since rare-earth ions with an even number of electrons can give singlet electronic crystal field levels that have no electronic magnetic moment to first order, initial studies focused on non-Kramers ions such as Eu3+, Pr3+, and Tm3+ doped into host materials with small nuclear magnetic moments or small abundances of

Spectral diffusion and decoherence of ensembles

The finite lifetime T1 of the excited electronic state establishes the minimum rate of decoherence, limiting the coherence lifetime T2 to a maximum value of T2=2T1. Homogeneous decoherence mechanisms, such as the excited-state lifetime and elastic and inelastic phonon scattering at higher temperatures produce a simple exponential decay of stored phase information with time constant T2, corresponding to a Lorentzian spectral linewidth Γh of a single optical center with a full-width at

Rare-earth materials for frequency and phase stabilization of laser sources in QIS

The success of implementing rare-earth materials for applications in QIS and SSH is dependent on the supporting and enabling technologies such as laser sources, detectors, new classes of materials, and cryogenics. Specialized laser sources with narrow sub-kilohertz linewidths and a very high degree of frequency, phase, and amplitude stability are an enabling component for many of these new applications.

Frequency references based on narrow spectral holes in the materials or on narrow

Specialized requirements and tradeoffs for quantum information applications

A universal requirement for materials involves achieving slow decoherence rates relative to the transition rate [99], [111]. As a result, large transition oscillator strengths and near-radiative limited excited-state lifetimes are desirable. Large oscillator strengths are also required to achieve the high optical densities needed for efficient storage. Other requirements and tradeoffs for QIS applications depend on specific protocols. For CRIB and gradient-echo memory, narrow inhomogeneous

Summary

The feasibility and eventual practicality of solid-state coherent optical information storage and processing devices depends on special resonant optical materials, among which rare-earth ions doped into dielectric crystals at cryogenic temperatures are one of the most promising candidates. Motivated by this, we provided a comprehensive overview of the properties of rare-earth-activated solids as well as a summary of the relevant materials studied by our laboratory and by other laboratories. In

Acknowledgements

The crystal for the passive dynamic spectral filtering method was grown by Scientific Materials Corp. of Bozeman, MT, USA. Funding for this research was provided in part by the Air Force Office of Scientific Research under Grant nos. F49620-97-1-0411, F49620-98-1-0171, and F49620-00-1-0314, and by the National Science Foundation under Grant no. 0903937-WR121. T.B. wishes to acknowledge financial support through the University of San Francisco faculty development fund.

References (111)

  • F. Schlottau et al.

    J. Lumin.

    (2004)
  • K.D. Merkel et al.

    J. Lumin.

    (2004)
  • R. Krishna Mohan et al.

    J. Lumin.

    (2007)
  • Z.W. Barber et al.

    J. Lumin.

    (2010)
  • C.W. Thiel et al.

    J. Lumin.

    (2010)
  • E.P. Chukalina et al.

    Phys. Lett. A

    (2000)
  • R.M. Macfarlane

    J. Lumin.

    (2007)
  • G.K. Liu et al.

    J. Lumin.

    (1987)
  • G.K. Liu et al.

    J. Lumin.

    (1988)
  • S.B. Altner et al.

    Chem. Phys. Lett.

    (1995)
  • R.M. Macfarlane

    J. Lumin.

    (2002)
  • Y. Sun et al.

    J. Lumin.

    (2002)
  • R.M. Macfarlane et al.

    Opt. Commun.

    (1981)
  • R.M. Macfarlane et al.

    J. Lumin.

    (2004)
  • C.W. Thiel et al.

    J. Lumin.

    (2010)
  • C.W. Thiel et al.

    J. Lumin.

    (2004)
  • O. Guillot-Noel et al.

    J. Alloys Compd.

    (2008)
  • S.R. Hastings-Simon et al.

    Opt. Commun.

    (2006)
  • M.U. Staudt et al.

    Opt. Commun.

    (2006)
  • A. Gocalinska et al.

    Opt. Mater.

    (2008)
  • P. Goldner et al.

    J. Alloys Compd.

    (2008)
  • R.M. Macfarlane et al.

    J. Lumin.

    (2000)
  • W. Tittel et al.

    Laser Photon. Rev.

    (2010)
  • M.P. Hedges et al.

    Nature

    (2010)
  • A.I. Lvovsky et al.

    Nat. Photon.

    (2009)
  • C. Simon et al.

    Eur. Phys. J. D

    (2010)
  • Imam Usmani et al.

    Nat. Commun.

    (2010)
  • H. Lin et al.

    Opt. Lett.

    (1995)
  • T.L. Harris et al.

    Opt. Lett.

    (1998)
  • A. Renn et al.

    J. Phys. Chem. A

    (2002)
  • Z. Cole et al.

    Appl. Phys. Lett.

    (2002)
  • V. Crozatier et al.

    IEEE J. Quantum Electron.

    (2004)
  • G.H. Dieke et al.

    Appl. Opt.

    (1963)
  • B.R. Judd

    Operator Techniques in Atomic Spectroscopy

    (1963)
  • B.G. Wybourne

    Spectroscopic Properties of Rare Earths

    (1965)
  • S. Hüfner

    Optical Spectra of Transparent Rare Earth Insulators

    (1978)
  • D.J. Newman et al.
  • G.K. Liu
  • R.W. Equall et al.

    Phys. Rev. Lett.

    (1994)
  • Thomas Böttger et al.

    Phys. Rev. B

    (2009)
  • J.H.Van Vleck

    J. Chem. Phys.

    (1937)
  • B.R. Judd

    Phys. Rev.

    (1962)
  • G.S. Ofelt

    J. Chem. Phys.

    (1962)
  • M.F. Reid
  • Thomas Böttger et al.

    Proc. SPIE

    (2003)
  • Thomas Böttger et al.

    Phys. Rev. B.

    (2006)
  • Thomas Böttger et al.

    Phys. Rev. B

    (2006)
  • Thomas Böttger et al.

    Phys. Rev. B

    (2008)
  • Y.C. Sun
  • A.M. Stoneham

    Rev. Mod. Phys.

    (1969)
  • Cited by (397)

    View all citing articles on Scopus
    View full text