Time-gated Einstein-Podolsky-Rosen correlation

Abstract

We experimentally demonstrate the creation and characterization of Einstein-Podolsky-Rosen ͑EPR͒ correlation between optical beams in a time-gated fashion. The correlated beams are created with two independent continuous-wave optical parametric oscillators and a half beam splitter. We define the temporal modes using a square temporal filter with duration T and make time-resolved measurements on the generated state. We observe correlations between the relevant conjugate variables in the temporal mode which correspond to EPR correlation. Our scheme is extendable to continuous-variable quantum teleportation of a non-Gaussian state defined in the time domain such as a superposition of coherent states.

Experimental realization of spatially separated entanglement with continuous variables using laser pulse trains

“…Once again, each quadrature value is obtained by integrating the sampled HD output over the time interval between successive pulses, i.e., the starting integration time “T” is chosen to obtain zero correlation coefficient. This method differs from that of previous works 11 25 using continuous wave light sources where the time-resolved analysis was only performed in a limited time windows or the Fourier transform was only calculated at one fixed frequency. This is also different from the previous pulsed scheme in which only one quadrature of each pulse was sampled 20 21 .…”

Electromagnetically Induced Transparency with Squeezed Vacuum

“…After the preparation period, the feedback voltage driving a PZT was held and the weak coherent light was turned off with AOM5. Eventually, the relative phase between the LO and the squeezed vacuum was kept during the measurement period [83].…”

Gaussian entanglement for quantum key distribution from a single-mode squeezing source

“…The less common entanglement-based schemes do not need signal modulation [10], and instead exploit directly the correlations in the field quadratures of an Einstein-Podolsky-Rosen (EPR) entangled state. EPR entangled states are usually generated by interfering two squeezed beams at a beam splitter [11][12][13][14][15][16][17][18][19][20][21][22].…”