ar X iv : 0 90 3 . 10 90 v 2 [ qu an t - ph ] 2 2 M ay 2 00 9 Interference contrast in multi - source few photon optics

ar X iv : 0 90 3 . 10 90 v 1 [ qu an t - ph ] 5 M ar 2 00 9 Interference contrast in multi - source few photon optics

Many recent experiments employ several parametric down conversion (PDC) sources to get multiphoton interference. Such interference has applications in quantum information. We study here how effects due to photon statistics, misalignment, and partial distinguishability of the PDC pairs originating from different sources may lower the interference contrast in the multiphoton experiments. PACS num...

ar X iv : 0 90 9 . 06 46 v 2 [ qu an t - ph ] 2 5 N ov 2 00 9 Time gating of heralded single photons for atomic memories

We demonstrate a method for time gating the standard heralded continuouswave (cw) spontaneous parametric down-converted (SPDC) single photon source by using pulsed pumping of the optical parametric oscillator (OPO) below threshold. The narrow bandwidth, high purity, high spectral brightness and the pseudo-deterministic character make the source highly suitable for light-atom interfaces with ato...

ar X iv : 0 90 5 . 21 92 v 1 [ as tr o - ph . C O ] 1 3 M ay 2 00 9 The 2 pt + : an enhanced 2 point correlation function

We introduce a new method for testing departure from isotropy of points on a sphere based on an enhanced form of the two-point correlation function that we named 2pt+. This method uses information from the two extra variables that define the vector between two points on a sphere. We show that this is a powerful method to test departure from isotropy of a distribution of points on a sphere espec...

ar X iv : 0 90 5 . 25 69 v 1 [ qu an t - ph ] 1 5 M ay 2 00 9 Dephasing of qubits by the Schrödinger cat

We study the dephasing of a single qubit coupled to a bosonic bath. In particular, we investigate the case when the bath is initially prepared in a pure state known as the Schrödinger cat. In clear contradistinction to the time-evolution of an initial coherent state, the time evolutions of the purity and the coherence factor now depend on the particular choice of the Schrödinger cat state. We a...

ar X iv : 0 90 3 . 05 62 v 1 [ as tr o - ph . G A ] 3 M ar 2 00 9 Introduction to Millimeter / Sub - Millimeter