  Efficient quantum memories will be an essential building block of large scale
networked quantum systems and provide a link between flying photonic qubits and
atomic or quasi-atomic local quantum processors. To provide a path to
scalability avoidance of bulky, difficult to maintain systems such as high
vacuum and low temperature cryogenics is imperative. Memory efficiencies above
50% are required to be operating above the quantum no-cloning limit. Such high
efficiencies have only been achieved in systems with photon sources tailored to
the memory bandwidth. In this paper we explore the combination of an ultralow
spectral bandwidth source of single photons from cavity-enhanced spontaneous
parametric down-conversion with a gas-ensemble atomic memory. Our rubidium
vapour gradient echo memory achieves 84$\pm$3% recall efficiency of single
photons: a record for an always-ready, hot, and vacuum system free optical
memory.
