We produce a 600-ns pulse of 1.86-dB squeezed vacuum at 795 nm in an optical parametric amplifier and store it in a rubidium vapor cell for 1 mus using electromagnetically induced transparency. The recovered pulse, analyzed using time-domain homodyne tomography, exhibits up to 0.21+/-0.04 dB of squeezing. We identify the factors leading to the degradation of squeezing and investigate the phase ...

A novel method of squeezing with optical pulses in a fiber ring reflector is demonstrated experimentally. Squeezing of greater than 5 +/- 0.3 dB has been observed. The pump is separated from the squeezed radiation with a fiber ring reflector and can be reused, in principle fully, as the local oscillator. The detection is at low frequencies (35-85 kHz) and is unaffected by guided-acoustic-wave B...

We introduce the nonlinear spin-coherent state (SCS) via its ladder operator formalism and propose a type of nonlinear SCS by the nonlinear time evolution of the SCS. By a new version of spectroscopic squeezing criteria we study the spin squeezing in both the SCS and the nonlinear SCS. The results show that the SCS is not squeezed in the x, y and z directions, and the nonlinear SCS may be squee...

Feature squeezing is a recently-introduced framework for mitigating and detecting adversarial examples. In previous work, we showed that it is effective against several earlier methods for generating adversarial examples. In this short note, we report on recent results showing that simple feature squeezing techniques also make deep learning models significantly more robust against the Carlini/W...

We examine the properties of an atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed light. We model the multimode dynamics of the output field and show that a significant amount of squeezing can be transferred from an optical mode to a propagating atom laser beam. We use this to demonstrate that two-mode squeezing can be used to produce twin atom laser beams with co...

The collisional interaction in a Bose condensate represents a non-linearity which in analogy with non-linear optics gives rise to unique quantum features. In this paper we apply a Monte Carlo method based on the positive P pseudo-probability distribution from quantum optics to analyze the efficiency of spin squeezing by collisions in a two-component condensate. The squeezing can be controlled b...

We present a scheme for achieving coherent spin squeezing of nuclear spin states in semiconductor quantum dots. The nuclear polarization dependence of the electron spin resonance generates a unitary evolution that drives nuclear spins into a collective entangled state. The polarization dependence of the resonance generates an area-preserving, twisting dynamics that squeezes and stretches the nu...

We address the propagation of twin-beam of radiation through Gaussian phase-sensitive channels, i.e. noisy channels with squeezed fluctuations. We find that squeezing the environment always reduces the survival time of entanglement in comparison to the case of simple dissipation and thermal noise. We also show that the survival time is further reduced if the squeezing phase of the fluctuations ...

We report the observation of more than 7 dB of vacuum squeezing from a below-threshold optical parametric oscillator (OPO). We discuss design criteria and experimental considerations for its optimization and demonstrate that the vacuum squeezing can be electro-optically transferred to a bright beam using a feed-forward loop. This is compared with the bright intensity squeezed beam generated by ...