arXiv subjects

P. Nussenzveig

Publications and source records attributed to P. Nussenzveig.

25 records · Page 2Linked to original sources

arXiv2004

Orbital angular momentum exchange in an optical parametric oscillator

We present a study of orbital angular momentum transfer from pump to down-converted beams in a type-II Optical Parametric Oscillator. Cavity and anisotropy effects are investigated and demostrated to play a central role in the transverse mode dynamics. While the idler beam can oscillate in a Laguerre-Gauss mode, the crystal birefringence induces an astigmatic effect in the signal beam that prevents the resonance of such mode.

physics.optics↗

arXiv2003

Noise spectroscopy of non-linear magneto optical resonances in Rb vapor

Nonlinear magneto-optical (NMO) resonances occurring for near-zero magnetic field are studied in Rb vapor using light-noise spectroscopy. With a balanced detection polarimeter, we observe high contrast variations of the noise power (at fixed analysis frequency) carried by diode laser light resonant with the 5S$_{1/2}(F=2) \to 5$P$_{1/2}(F=1) $ transition of $^{87}$Rb and transmitted through a rubidium vapor cell, as a function of magnetic field $B$. A symmetric resonance doublet of anti-correlated noise is observed for orthogonal polarizations around $B=0 $ as a manifestation of ground state coherence. We also observe sideband noise resonances when the magnetic field produces an atomic Larmor precession at a frequency corresponding to one half of the analysis frequency. The resonances on the light fluctuations are the consequence of phase to amplitude noise conversion owing to nonlinear coherence effects in the response of the atomic medium to the fluctuating field. A theoretical model (derived from linearized Bloch equations) is presented that reproduces the main qualitative features of the experimental signals under simple assumptions.

physics.atom-ph↗

arXiv2002

Entanglement between two macroscopic fields by coherent atom-mediated exchange of photons

Using two different criteria for continuous variable systems we demonstrated that pump and probe beams became quantum correlated in a situation of Electromagnetically Induced Transparency in a sample of Rb atoms. Our result combines two important features for practical implementations in the field of quantum information processing. Namely, we proved the existence of entanglement between two macroscopic light beams, and this entanglement is intrinsically associated to a strong coherence in an atomic medium.

quant-ph↗

arXiv2002

Super-poissonian photon statistics and correlations between pump and probe fields in Electromagnetically Induced Transparency

We have measured the photon statistics of pump and probe beams after interaction with Rb atoms in a situation of Electromagnetically Induced Transparency. Both fields present super-poissonian statistics and their intensities become correlated, in good qualitative agreement with theoretical predictions in which both fields are treated quantum-mechanically. The intensity correlations measured are a first step towards the observation of entanglement between the fields.

quant-ph↗

arXiv2001

Classical Analog of Electromagnetically Induced Transparency

We present a classical analog for Electromagnetically Induced Transparency (EIT). In a system of just two coupled harmonic oscillators subject to a harmonic driving force we can reproduce the phenomenology observed in EIT. We describe a simple experiment performed with two linearly coupled RLC circuits which can be taught in an undergraduate laboratory class.

quant-ph↗

arXiv2001

Collective Rabi Oscillations and Cold Collisions

We examine cold atomic collisions within a resonant optical cavity. The quantized cavity mode can be used to manipulate the collisions between the cold atoms, such that periodic exchange of excitations between the atoms and the electromagnetic field strongly alters the collision dynamics. A colliding pair of atoms can thereby oscillate between its ground and excited states during the collision time. Using a semiclassical model, it can be predicted that such Rabi-like oscillations are revealed in the atomic trap-loss probabilities, which show maxima and minima as a function of the detuning between the frequencies of the mode and the atomic transition.

quant-ph↗

arXiv2001

Interfering with decay of a single photon in microwave cavities through single photon quantum non-demolition scheme

The decay of a single photon in a microwave cavity is shown to be retarded by interaction with a resonant two-level atom in the experimental setup recently developed by Nogues and co-workers [see G. Nogues, A. Rauschenbeutel, S. Osnaghi, M. Brune, J. M. Raimond and S. Haroche, Nature vol 400, 239(1999)]. The effect may be interpreted in terms of the temporary removal of the photon from the cavity thereby protecting it from the effects of the environment to wich the cavity is coupled. Realistic parameters lead to a significative increase of the survival probability of the photon subsequently to the monitoring interaction.

quant-ph↗