Agarwal, Girish
Recent Submissions

Nonclassical correlation of polarisation entangled photons in a biexcitonexciton cascade
(Journal of Physics B: Atomic, Molecular and Optical Physics, 20081110)We develop a theoretical model to study the IntensityIntensity correlation of polarisation entangled photons emitted in a biexcitonexciton cascade. We calculate the degree of correlation and show how polarisation ... 
Quantum interferences in cooperative Dicke emission from spatial variation of laser phase
(Physical Review Letters, 20081006)We report generation of a new quantum interference effect in spontaneous emission from a resonantly driven system of two identical twolevel atoms due to the spatial variation of the laser phase at the positions of the ... 
Entanglement of two distant BoseEinstein condensates by detection of Braggscattered photons
(Physical Review A, 20080731)We show that it is possible to generate entanglement between two distant BoseEinstein condensates by detection of Hanbury BrownTwiss type correlations in photons Braggscattered by the condensates. Upon coincident detection ... 
PhotonPhoton Correlations as a Probe of Vacuum Induced Coherence Effects
(Physical Review A, 20080327)We present new experimental implications of the effects of vacuum induced coherence on the photon photon correlation in the pipolarized fluorescence in j = 1/2 to j = 1/2 transition. These effects should be thus observable ... 
Electromagnetic field induced modification of branching ratios for emission in structured vacuum
(New Journal of Physics, 20080117)We report a fundamental effect of the electromagnetic field induced modification of the branching ratios for emission into several final states. The modifications are especially significant if the vacuum into which the ... 
Quantum imaging with incoherent photons
(Physical Review Letters, 20070928)We propose a technique to obtain subwavelength resolution in quantum imaging with potentially 100% contrast using incoherent light. Our method requires neither pathentangled number states nor multiphoton absorption. The ... 
Solitons in interacting Dicke models of coupled cavities with twolevel systems
(20070705)We consider an array of coupled optical cavities, each containing a multiatom ensemble. We show that the nonlinearity inherent in the cooperative dynamics of the atoms in each ensemble coupled to the respective cavity ... 
Realization of quantummechanical weak values of observables using entangled photons
(Physical Review A, 20070412)We present a scheme for realization of quantummechanical weak values of observables using entangled photons produced in parametric downconversion. We consider the case when the signal and idler modes are respectively in ... 
Laser induced resonance shifts of single molecules selfcoupled by a metallic surface
(Physical Review Letters, 20070405)The spectral properties of single molecules placed near a metallic surface are investigated at low temperatures. Because of the high quality factor of the optical resonance, a laser induced shift of the molecular lines is ... 
Fast light solitons in resonant media
(Physical Review A, 20070405)Using the structure of the MaxwellSchrodinger equations in twolevel systems in the transient domain, we derive both singlesoliton and multisoliton (2n pi pulse) solutions associated with fast light in resonant media. ... 
Measurementinduced spatial modulation of spontaneous decay and photon arrival times
(Physical Review A, 20061220)We report a way of manipulating the spontaneous emission process leading to a spatial modulation of spontaneous decay. The effect is observed in the case of coherently driven atoms separated by less than a transition ... 
Nonclassicality and decoherence of photonsubtracted squeezed states
(Physical Review A, 20061204)We discuss nonclassical properties of singlephoton subtracted squeezed vacuum states in terms of the subPoissonian statistics and the negativity of the Wigner function. We derive a compact expression for the Wigner ... 
Towards Heisenberg limit in magnetometry with parametric down converted photons
(Physical Review A, 20061116)Recent theoretical and experimental papers have shown how one can achieve Heisenberg limited measurements by using entangled photons. Here we show how the photons in noncollinear down conversion process can be used for ... 
Competition between electromagnetically induced transparency and Raman processes
(Physical Review A, 20061005)We present a theoretical formulation of competition among electromagnetically induced transparency (EIT) and Raman processes. The latter become important when the medium can no longer be considered to be dilute. Unlike the ... 
Extreme subwavelength atom localization via coherent population trapping
(Journal of Physics B: Atomic, Molecular and Optical Physics, 20060906)We demonstrate an atom localization scheme based on monitoring of the atomic coherences. We consider atomic transitions in a Lambda configuration where the control field is a standingwave field. The probe field and the ... 
Entanglement by linear SU(2) transformations: generation and evolution of quantum vortex states
(Journal of Physics A: Mathematical and General, 20060731)We consider the evolution of a twomode system of bosons under the action of a Hamiltonian that generates linear SU(2) transformations. The Hamiltonian is generic in that it represents a host of entanglement mechanisms, ... 
Interferences in parametric interactions driven by quantized fields
(Physical Review Letters, 20060711)We report interferences in the quantum fluctuations of the output of a parametric amplifier when the cavity is driven by a quantized field at the signal frequency. The interferences depend on the phase fluctuations of the ... 
New class of exact solitary wave solutions of one dimensional GrossPitaevskii equation
(Physical Review E, 20060519)We present a large family of exact solitary wave solutions of the one dimensional GrossPitaevskii equation, with timevarying scattering length and gain/loss, in both expulsive and regular parabolic confinement regimes. ... 
Twophoton excitation dynamics in bound twobody Coulomb systems including ac Stark shift and ionization
(Physical Review A, 20060503)One of the dominant systematic effects that shift resonance lines in highprecision measurements of twophoton transitions is the dynamic ac[1] Stark shift. For suitable laser frequencies, the ac Stark shift acquires an ... 
Ultraslow light in inhomogeneously broadened media
(Physical Review A, 20060419)We calculate the characteristics of ultraslow light in an inhomogeneously broadened medium. We present analytical and numerical results for the group delay as a function of power of the propagating pulse. We apply these ...