Quantum Memory with a Single Photon in a Cavity

Abstract

The quantum information carried by a two-level atom was transferred to a high-Q cavity and, after a delay, to another atom. We realized in this way a quantum memory made of a field in a superposition of 0 and 1 photon Fock states. We measured the "holding time" of this memory corresponding to the decay of the field intensity or amplitude at the single photon level. This experiment implements a step essential for quantum information processing operations. [S0031-9007(97)03701-0]

Single photon quantum filtering using non-Markovian embeddings

“…In recent years, single photon states of light and superpositions of coherent states have become increasingly important owing to applications in quantum technology, in particular quantum computing and quantum information systems [1][2][3][4][5]. For instance, the light may interact with a system, say an atom, quantum dot or cavity, and this system may be used as a quantum memory [3], or to control the pulse shape of the single photon state [4].…”

“…For instance, the light may interact with a system, say an atom, quantum dot or cavity, and this system may be used as a quantum memory [3], or to control the pulse shape of the single photon state [4]. When light interacts with a quantum system, information about the system is contained in the scattered light (output) and this may be used to monitor or control the system.…”

Probing a Single Isolated Electron: New Measurements of the Electron Magnetic Moment and the Fine Structure Constant

“…At the time of this observation, only zero-and one-photon Fock states, |n = 0 and |n = 1 , had previously been observed for a radiation mode of a cavity [10,11], though efforts were underway to observe two-photon and higher Fock states [12]. A ground state occupation fraction P = 0.95 was reported.…”

Principles and applications of quantum control engineering

“…However, there has been considerable interest recently in non-classical field states ( figure 14), specifically, states corresponding to a single photon (or more generally Fock states) [40,41] and superpositions of coherent states. The former can now be generated on demand using state-of-the-art experimental techniques, while the latter correspond to the so-called cat states.…”