ar X iv : 1 40 1 . 11 55 v 1 [ qu an t - ph ] 6 J an 2 01 4 Two - valued states on Baer ∗ - semigroups

ar X iv : 1 11 1 . 37 97 v 1 [ qu an t - ph ] 1 6 N ov 2 01 1 Prony ’ s method and the connected – moments expansion

ar X iv : 1 40 3 . 36 47 v 1 [ qu an t - ph ] 1 4 M ar 2 01 4 Heisenberg Limit Superradiant Super - resolving Metrology

We propose a superradiant metrology scheme to achieve Heisenberg limit super-resolving displacement measurement by encoding multiple light momenta into a three-level atomic ensemble. We use 2N coherent pulses to prepare a single excitation superradiant state in a superposition of two timed Dicke states that are 4N light momenta apart in the momentum space. The phase difference between these two...

ar X iv : 1 20 1 . 37 97 v 2 [ qu an t - ph ] 1 2 M ar 2 01 2 Two - photon path - entangled states in multi - mode waveguides

We experimentally show that two-photon path-entangled states can be coherently manipulated by multi-mode interference in multi-mode waveguides. By measuring the output two-photon spatial correlation function versus the phase of the input state, we show that multi-mode waveguides perform as nearly-ideal multi-port beam splitters at the quantum level, creating a large variety of entangled and sep...

ar X iv : 1 41 2 . 54 85 v 1 [ qu an t - ph ] 1 7 D ec 2 01 4 A short note on passivity , complete passivity and virtual temperatures

We give a simple and intuitive proof that the only states which are completely passive, i.e. those states from which work cannot be extracted even with infinitely many copies, are Gibbs states at positive temperatures. The proof makes use of the idea of virtual temperatures, i.e. the association of temperatures to transitions. We show that (i) passive states are those where every transition is ...

ar X iv : 1 40 6 . 42 52 v 1 [ qu an t - ph ] 1 7 Ju n 20 14 Time - frequency quantum process tomography of para - metric down - conversion

Parametric down-conversion (PDC) is the established standard for the practical generation of a multiplicity of quantum optical states. These include two-mode squeezed vacuum1, heralded non-Gaussian states2–6 and entangled photon pairs7, 8. Detailed theoretical studies provide insight into the time-frequency (TF) structure of PDC, which are governed by the complex-valued joint spectral amplitude...