Atomic frequency comb memory with spin-wave storage in 153Eu3 +:Y2SiO5
153 Eu 3 + :Y 2 SiO 5 is a very attractive candidate for a long-lived, multimode quantum memory due to the long spin coherence time (~15 ms), the relatively large hyperfine splitting (100 MHz) and the narrow optical homogeneous linewidth (~100 Hz). Here we show an atomic frequency comb memory with spin-wave storage in a promising material 153 Eu 3 + :Y 2 SiO 5 , reaching storage times slightly beyond 10 μs. We analyse the efficiency of the storage process and discuss ways of improving it. We also measure the inhomogeneous spin linewidth of 153 Eu 3 + :Y 2 SiO 5 , which we find to be 69 ± 3 kHz. These results represent a further step towards realizing a long-lived, multimode solid-state quantum memory.