Now showing items 1-20 of 42

    • Cavity-mediated long-range interaction for fast multiqubit quantum logic operations 

      Kapale, K. T.; Agarwal, Girish Saran; Scully, Marlan O.; Agarwal, Girish Saran (Physical Review A, 2005-11-05)
      Interactions among qubits are essential for performing two-qubit quantum logic operations. However, nature gives us only nearest neighbor interactions in simple and controllable settings. Here we propose a strategy to ...
    • Competition between electromagnetically induced transparency and Raman processes 

      Agarwal, Girish Saran; Dey, T. N.; Gauthier, Daniel; Agarwal, Girish Saran (Physical Review A, 2006-10-05)
      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 ...
    • DC field induced enhancement and inhibition of spontaneous emission in a cavity 

      Agarwal, Girish Saran; Pathak, P. K.; Agarwal, Girish Saran (Physical Review A, 2004-08-20)
      We demonstrate how spontaneous emission in a cavity can be controlled by the application of a dc field. The method is specially suitable for Rydberg atoms. We present a simple argument based on Stark shifts for the control ...
    • Electromagnetic field induced modification of branching ratios for emission in structured vacuum 

      Das, S.; Agarwal, Girish Saran; Das, S.; Agarwal, Girish Saran (New Journal of Physics, 2008-01-17)
      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 ...
    • Electromagnetically induced magnetochiral anisotropy in a resonant medium 

      Sautenkov, V. A.; Rostovtsev, Y. V.; Chen, Hua; Hsu, P.; Agarwal, Girish Saran; Scully, Marlan O.; Agarwal, Girish Saran (Physical Review Letters, 2005-07-14)
      Chirality has been extensively studied for well over a century, and its potential applications range from optics to chemistry, medicine, and biology. Ingenious experiments have been designed to measure this naturally small ...
    • Entanglement by linear SU(2) transformations: generation and evolution of quantum vortex states 

      Agarwal, Girish Saran; Banerji, J.; Agarwal, Girish Saran (Journal of Physics A: Mathematical and General, 2006-07-31)
      We consider the evolution of a two-mode 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, ...
    • Entanglement of two distant Bose-Einstein condensates by detection of Bragg-scattered photons 

      Deb, B.; Agarwal, Girish Saran; Agarwal, Girish Saran (Physical Review A, 2008-07-31)
      We show that it is possible to generate entanglement between two distant Bose-Einstein condensates by detection of Hanbury Brown-Twiss type correlations in photons Bragg-scattered by the condensates. Upon coincident detection ...
    • Entangling pairs of nano-cantilevers, Cooper-pair boxes and mesoscopic teleportation 

      Bose, S.; Agarwal, Girish Saran; Agarwal, Girish Saran (New Journal of Physics, 2006-03-07)
      We propose two schemes to establish entanglement between two mesoscopic quantum systems through a third mesoscopic quantum system. The first scheme entangles two nano-mechanical oscillators in a non-Gaussian entangled state ...
    • Extreme subwavelength atom localization via coherent population trapping 

      Agarwal, Girish Saran; Kapale, K. T.; Agarwal, Girish Saran (Journal of Physics B: Atomic, Molecular and Optical Physics, 2006-09-06)
      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 standing-wave field. The probe field and the ...
    • Fast light solitons in resonant media 

      Agarwal, Girish Saran; Dey, T. N.; Agarwal, Girish Saran (Physical Review A, 2007-04-05)
      Using the structure of the Maxwell-Schrodinger equations in two-level systems in the transient domain, we derive both single-soliton and multisoliton (2n pi pulse) solutions associated with fast light in resonant media. ...
    • Generation of a superposition of multiple mesoscopic states of radiation in a resonant cavity 

      Pathak, P. K.; Agarwal, Girish Saran; Pathak, P. K.; Agarwal, Girish Saran (Physical Review A, 2005-06-27)
      Using resonant interaction between atoms and the field in a high quality cavity, we show how to generate a superposition of many mesoscopic states of the field. We study the quasi-probability distributions and demonstrate ...
    • Generation of Werner states via collective decay of coherently driven atoms 

      Agarwal, Girish Saran; Kapale, K. T.; Agarwal, Girish Saran (Physical Review A, 2006-03-08)
      We show deterministic generation of Werner states as a steady state of the collective decay dynamics of a pair of neutral atom coupled to a leaky cavity and strong coherent drive. We also show how the scheme can be extended ...
    • Implementing Deutsch-Jozsa algorithm using light shifts and atomic ensembles 

      Dasgupta, S.; Biswas, A.; Agarwal, Girish Saran; Agarwal, Girish Saran (Physical Review A, 2005-01-27)
      We present an optical scheme to implement the Deutsch-Jozsa algorithm using ac Stark shifts. The scheme uses an atomic ensemble consisting of four-level atoms interacting dispersively with a field. This leads to a Hamiltonian ...
    • Inducing disallowed two-atom transitions with temporally entangled photons 

      Muthukrishnan, A.; Agarwal, Girish Saran; Scully, Marlan O.; Agarwal, Girish Saran (Physical Review Letters, 2004-08-25)
      Two uncoupled two-level atoms cannot be jointly excited by classical light under general circumstances, due to destructive interference of excitation pathways in two-photon absorption. However, with temporally entangled ...
    • Inseparability inequalities for higher order moments for bipartite systems 

      Agarwal, Girish Saran; Biswas, A.; Agarwal, Girish Saran (New Journal of Physics, 2005-10-07)
      There are several examples of bipartite entangled states of continuous variables for which the existing criteria for entanglement using the inequalities involving the second-order moments are insufficient. We derive new ...
    • Interferences in parametric interactions driven by quantized fields 

      Agarwal, Girish Saran; Agarwal, Girish Saran (Physical Review Letters, 2006-07-11)
      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 ...
    • Langevin analysis of fundamental noise limits in coherent anti-Stokes Raman spectroscopy 

      Das, Kunal K.; Agarwal, Girish Saran; Golubev, Y. M.; Scully, Marlan O.; Agarwal, Girish Saran (Physical Review A, 2005-01-04)
      We use a Langevin approach to analyze the quantum noise in coherent anti-Stokes Raman spectroscopy in several experimental scenarios: with continuous-wave input fields acting simultaneously and with fast sequential pulsed ...
    • Large two atom two photon vacuum Rabi oscillations in a high quality cavity 

      Pathak, P. K.; Agarwal, Girish Saran; Agarwal, Girish Saran (Physical Review A, 2004-10-11)
      We predict large cooperative effect involving two atom two photon vacuum Rabi oscillations in a high quality cavity.
    • Laser induced resonance shifts of single molecules self-coupled by a metallic surface 

      Labeau, O.; Tamarat, P.; Courtois, H.; Agarwal, Girish Saran; Lounis, B.; Agarwal, Girish Saran (Physical Review Letters, 2007-04-05)
      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 ...
    • Measurement-induced spatial modulation of spontaneous decay and photon arrival times 

      Zanthier, J.; Bastin, Ted; Agarwal, Girish Saran; Agarwal, Girish Saran (Physical Review A, 2006-12-20)
      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 ...