TY - JOUR TI - A spectral hole memory for light at the single photon level AU - Kutluer, Kutlu AU - Pascual-Winter, María Florencia AU - Dajczgewand, Julian AU - Ledingham, Partick M. AU - Mazzera, Margherita AU - Chanelière, Thierry AU - de Riedmatten, Hugues T2 - Physical Review A AB - We demonstrate a solid state spin-wave optical memory based on stopped light in a spectral hole. A long lived narrow spectral hole is created by optical pumping in the inhomogeneous absorption profile of a Pr$^{3+}$:Y$_2$SiO$_5$ crystal. Optical pulses sent through the spectral hole experience a strong reduction of their group velocity and are spatially compressed in the crystal. A short Raman pulse transfers the optical excitation to the spin state before the light pulse exits the crystal, effectively stopping the light. After a controllable delay, a second Raman pulse is sent, which leads to the emission of the stored photons. We reach storage and retrieval efficiencies for bright pulses of up to $39\,\%$ in a $5 \,\mathrm{mm}$-long crystal. We also show that our device works at the single photon level by storing and retrieving $3\,\mathrm{\mu s}$-long weak coherent pulses with efficiencies up to $31\,\%$, demonstrating the most efficient spin-wave solid state optical memory at the single-photon level so far. We reach an unconditional noise level of $(9\pm1)\times 10^{-3}$ photons per pulse in a detection window of $4\,\mathrm{\mu s}$ leading to a signal-to-noise ratio of $33 \pm 4$ for an average input photon number of 1, making our device promising for long-lived storage of non-classical light. DA - 2016/04/08/ PY - 2016 DO - 10.1103/PhysRevA.93.040302 DP - arXiv.org VL - 93 IS - 4 SP - 040302 J2 - Phys. Rev. A SN - 2469-9926, 2469-9934 UR - http://arxiv.org/abs/1509.03145 Y2 - 2019/07/31/11:05:35 KW - Margherita Mazzera KW - QPL KW - Quantum Physics ER -