Scalable time reversal of Raman echo quantum memory and quantum waveform conversion of light pulse

Abstract

We have found a new hidden symmetry of time reversal light-atom interaction in the photon echo quantum memory with Raman atomic transition. The time-reversed quantum memory creates generalized conditions for the ideal compression/decompression of time duration of the input light pulses and its wavelength. Based on a general analytical approach to this scheme, we have studied the optimal conditions for the light field compression/decompression in resonant atomic systems characterized by realistic spectral properties. The demonstrated necessary conditions for the effective quantum conversion of the light waveform and wavelength are also discussed for various possible realizations of the quantum memory scheme. The performed study promises new capabilities for fundamental study of the light-atom interaction and deterministic quantum manipulation of the light field, significant for quantum communication and quantum computing.

All-optical quantum storage based on spatial chirp of the control field

“…However for sufficient large one-photon detuning compared to the Rabi frequency (in the example provided in Sec. V, this ratio is ≈ 10), such negative influence is negligible [33]. The collective atomic operators are defined as the density of the single-atom operators…”

Broadband quantum memory in a cavity via zero spectral dispersion

“…After the signal pulse is absorbed and the control fields are adiabatically switched off as discussed in [32], spectral components of the incoming field are stored on the longlived coherence P j 12 of the corresponding resonant atoms (corrected by AC-Stark shift):…”

Configurable Unitary Transformations and Linear Logic Gates Using Quantum Memories

“…The temporal mode ofÊ in and the spatial mode ofŜ will depend on the particular method of storage; however, we assume thatÊ in is tailored such that the mappinĝ E in →Ŝ is efficient and reversible. Candidate storage methods include using appropriate temporal shaping of a strong coupling field [6,[12][13][14] or a reversible distribution of two-photon detunings [15][16][17]. Configurable beamsplitting into temporal modes has been demonstrated for both of these storage methods [18,19]; we show that extending these memories to operate on modes that are separated in frequency allows more general operations.We consider a three-level system that includes multiple signal fields which are separated in frequency.…”