  Just as classical information systems require buffers and memory, the same is
true for quantum information systems. The potential that optical quantum
information processing holds for revolutionising computation and communication
is therefore driving significant research into developing optical quantum
memory. A practical optical quantum memory must be able to store and recall
quantum states on demand with high efficiency and low noise. Ideally, the
platform for the memory would also be simple and inexpensive. Here, we present
a complete tomographic reconstruction of quantum states that have been stored
in the ground states of rubidium in a vapour cell operating at around 80$^o$C.
Without conditional measurements, we show recall fidelity up to 98% for
coherent pulses containing around one photon. In order to unambiguously verify
that our memory beats the quantum no-cloning limit we employ state independent
verification using conditional variance and signal transfer coefficients.

Quantum Physics