Time-delayed interference of a photon and the one-photon echo in media with phase memory

S. A. Moiseev

S. A. Moiseev, M. I. Noskov

Currently, it is obvious [1] that nonstationary tasks of quantum mechanics in more degree differ from those of classical physics than stationary ones. Accordingly, time- domain quantum optics experiments are very important for deepening our knowledge of quantum dynamics. It appears that a single-photon wave (SPW-) packets [2] are the best objects of quantum optics for investigation of the quantum dynamics at macroscopic level. One of the fundamental problems herein is the comprehension of interactions of quantum fields (SPW4MIN and TPW-packets) with macroscopic media. In particular, this is immediately associated with development of our knowledge about the fundamental properties of the irreversibility and of detecting quantum fields. At present, our notion about interaction of quantum fields with a detector, is mainly based on the phenomenological approaches to the properties of the detector [3]. That is why more exact quantum models of macroscopic detectors must be investigated. One of the macroscopic objects, which can be interesting for these purposes is the resonant quantum (Two-,Three-level) medium with phase memory intensively studied in coherent optics. Unusual properties of quantum time-domain interference effects and of photon echoes initiated in resonant media by interactions with an SPW-packet, have been predicted in our works 4LB4-6]. In the present paper study of the quantum dynamics at interaction of the field with the medium we will carry out by investigation of the two photon echo properties. At that, we consider interaction of a three- level (TL-) medium with polarized two-photon wave packets for the purpose of eliciting new nonclassical polarization properties in quantum dynamics of the echo signals.

Sergey A. Moiseev

A new version of time-delayed quantum interference of photons is proposed, which may be manifested in the emergence of a single-photon echo signal in coherent three-level macroscopic media. Nonclassical properties of this type of interference, reflected in peculiarities of the interaction between the field and the medium, are analysed along with the properties of the emitted echo signal.

A. R. Kessel, S. A. Moiseev

Nicolas Gisin, Sergey A. Moiseev, Christoph Simon

Quantum memories based on the photon-echo principle (with controlled reversible inhomogeneous broadening) allow in principle perfect reconstruction of the stored light. In the retrieval process, the envelope of the absorbed wave packet is reversed in time, but the evolution of the phase of the carrier wave is unchanged. We discuss the consequences of this fact for the relative phase of pulses with a certain time delay, and thus for the storage of time-bin qubits. As an illustration, we show that the combination of photon-echo-based memories and unbalanced interferometers leads to a counterintuitive interference effect, allowing one to measure a path length difference $\ensuremath{\Delta}L$ using pulses that are much shorter than $\ensuremath{\Delta}L$.

Ulf Elman, Stefan Kröll