Tm:LiNbO3 waveguides: a novel material candidate for quantum memories

Quantum memories, a key resource for many quantum communication and computing applications, require the possibility to reversibly transfer quantum information between photos and atoms. For instance, quantum memories are the main ingredient of quantum repeaters, essential components in long distance quantum cryptography. High recall efficiency, long storage times, and the possibility to store short pulses with high fidelity are the most important properties to be achieved in these devices. Determining the best approaches for implementation of quantum memories, as well as finding appropriate storage materials, is a field of extensive current research. In this presentation, we introduce our approach to quantum memories, which is based on controlled reversible inhomogeneous broadening (CRIB) of a narrow absorption line [1], and we present first spectroscopic investigations of a novel and promising material candidate: Thulium doped Lithium Niobate waveguides. We discuss our findings in view of the requirements for quantum memories. 1. M. Nilson, and S. Kroll, Opt. Commun. Vol. 247, No. 4-6 (2005). 2. A. L. Alexander, J. J. Longdell, M. J. Sellars, and N. B. Manson, Phys. Rev. Lett. 96, 043602 (2006). 3. B. Kraus, W. Tittel, N. Gisin, M. Nilsson, S. Kroll, and J. I. Cirac, Phys. Rev. A. 73, 020302(R) (2006).