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Local Pt Invariance And Supersymmetric Parametric Oscillators, Ramy El-Ganainy, Konstantinos G. Makris, Demetrios N. Christodoulides
Local Pt Invariance And Supersymmetric Parametric Oscillators, Ramy El-Ganainy, Konstantinos G. Makris, Demetrios N. Christodoulides
Faculty Bibliography 2010s
We introduce the concept of local parity-time symmetric (PT) invariance in optical waveguides (or cavity) structures. Starting from a Lagrangian formalism, we establish the connection between light dynamics in these configurations and the seemingly different physics of "supersymmetric" parametric oscillators. Using this powerful tool, we present analytical solutions for optical beam propagation in local PT-invariant coupled systems and we show that the intensity tunneling between the two channels critically depends on the initial conditions. For unbalanced inputs, symmetric as well as asymmetric power evolution can be observed depending on the excitation channel. On the other hand, under certain physical conditions, …
Phase-Unlocked Hong-Ou-Mandel Interferometry, Ayman F. Abouraddy, Timothy M. Yarnall, Giovanni Di Giuseppe
Phase-Unlocked Hong-Ou-Mandel Interferometry, Ayman F. Abouraddy, Timothy M. Yarnall, Giovanni Di Giuseppe
Faculty Bibliography 2010s
There is a fundamental dimensional mismatch between the Hong-Ou-Mandel (HOM) interferometer and two-photon (2P) states: while the latter are represented using two temporal (or spectral) dimensions, the HOM interferometer allows access to only one temporal dimension. We introduce a linear 2P interferometer containing two independent delays spanning the 2P state. By "unlocking" the fixed phase relationship between the interfering 2P probability amplitudes in a HOM interferometer, one of these probability amplitudes now serves as a delay-free 2P reference against which the other beats, thereby resolving ambiguities in 2P state identification typical of HOM interferometry and extending its utility to a …
Driven Translocation Of A Semi-Flexible Chain Through A Nanopore: A Brownian Dynamics Simulation Study In Two Dimensions, Ramesh Adhikari, Aniket Bhattacharya
Driven Translocation Of A Semi-Flexible Chain Through A Nanopore: A Brownian Dynamics Simulation Study In Two Dimensions, Ramesh Adhikari, Aniket Bhattacharya
Faculty Bibliography 2010s
We study translocation dynamics of a semi-flexible polymer chain through a nanoscopic pore in two dimensions using Langevin dynamics simulation in presence of an external bias F inside the pore. For chain length N and stiffness parameter kappa(b) considered in this paper, we observe that the mean first passage time < tau > increases as < tau(kappa(b)) > similar to < tau(kappa(b) = 0) > l(p)(aN), where kappa(b) and l(p) are the stiffness parameter and persistence length, respectively, and a(N) is a constant that has a weak N dependence. We monitor the time dependence of the last monomer x(N)(t) at the cis compartment and calculate the tension propagation time (TP) t(tp) …
Theory Of Radiative Electron Attachment To Molecules: Benchmark Study Of Cn, Nicolas Douguet, Samantha Fonseca Dos Santos, Maurice Raoult, Olivier Dulieu, Ann E. Orel, Viatcheslav Kokoouline
Theory Of Radiative Electron Attachment To Molecules: Benchmark Study Of Cn, Nicolas Douguet, Samantha Fonseca Dos Santos, Maurice Raoult, Olivier Dulieu, Ann E. Orel, Viatcheslav Kokoouline
Faculty Bibliography 2010s
We have developed an approach based on first principles to study the process of radiative electron attachment (REA) to linear molecules of astrophysical interest in collisions between the molecules and electrons at energies below 1 eV. The approach is based on accurate ab initio calculations of electronic bound and continuum states of the negative ion. The electronic continuum states are obtained with the complex-Kohn variational method. The benchmark calculation for the REA to the simplest negative ion CN-, which was recently observed in the interstellar medium, has produced a relatively low rate coefficient alpha(T) = 7.3 x 10(-16) cm(3)/s at …
Blueshifted Continuum Peaks From Filamentation In The Anomalous Dispersion Regime, Magali Durand, Khan Lim, Vytautas Jukna, Erik Mckee, Matthieu Baudelet, Aurèlien Houard, Martin Richardson, Andrè Mysyrowicz, Arnaud Couairon
Blueshifted Continuum Peaks From Filamentation In The Anomalous Dispersion Regime, Magali Durand, Khan Lim, Vytautas Jukna, Erik Mckee, Matthieu Baudelet, Aurèlien Houard, Martin Richardson, Andrè Mysyrowicz, Arnaud Couairon
Faculty Bibliography 2010s
Filamentation in the anomalous dispersion regime is experimentally shown to give rise to an extreme blueshifted continuum peak in the visible region even when the filament is formed by near-infrared pulses. Measurements and numerical simulations allow us to identify this peak as an axial component of the conical emission. Its features are characterized and quantitatively reproduced by the effective three-wave mixing model.
Spectral Moment Sum Rules For The Retarded Green's Function And Self-Energy Of The Inhomogeneous Bose-Hubbard Model In Equilibrium And Nonequilibrium, J. K. Freericks, V. Turkowski, H. R. Krishnamurthy, M. Knap
Spectral Moment Sum Rules For The Retarded Green's Function And Self-Energy Of The Inhomogeneous Bose-Hubbard Model In Equilibrium And Nonequilibrium, J. K. Freericks, V. Turkowski, H. R. Krishnamurthy, M. Knap
Faculty Bibliography 2010s
We derive exact expressions for the zeroth and the first three spectral moment sum rules for the retarded Green's function and for the zeroth and the first spectral moment sum rules for the retarded self-energy of the inhomogeneous Bose-Hubbard model in nonequilibrium, when the local on-site repulsion and the chemical potential are time-dependent, and in the presence of an external time-dependent electromagnetic field. We also evaluate these expressions for the homogeneous case in equilibrium, where all time dependence and external fields vanish. Unlike similar sum rules for the Fermi-Hubbard model, in the Bose-Hubbard model case, the sum rules often depend …
Fidelity Of The Surface Code In The Presence Of A Bosonic Bath, P. Jouzdani, E. Novais, E. R. Mucciolo
Fidelity Of The Surface Code In The Presence Of A Bosonic Bath, P. Jouzdani, E. Novais, E. R. Mucciolo
Faculty Bibliography 2010s
We study the resilience of the surface code to decoherence caused by the presence of a bosonic bath. This approach allows us to go beyond the standard stochastic error model commonly used to quantify decoherence and error threshold probabilities in this system. The full quantum mechanical system-bath dynamics is computed exactly over one quantum error correction cycle. Since all physical qubits interact with the bath, space-time correlations between errors are taken into account. We compute the fidelity of the surface code as a function of the quantum error correction time. The calculation allows us to map the problem onto an …
Laser-Controlled Rotational Cooling Of Na-2 Based On Exceptional Points, Viatcheslav Kokoouline, A. Wearne, R. Lefebvre, O. Atabek
Laser-Controlled Rotational Cooling Of Na-2 Based On Exceptional Points, Viatcheslav Kokoouline, A. Wearne, R. Lefebvre, O. Atabek
Faculty Bibliography 2010s
Exceptional points (EPs) corresponding to resonance coalescence (i.e., complex energy degeneracy and identical wave functions) occur in many areas of non-Hermitian physics and, in particular, in laser-induced molecular dynamics for specific choices of two control parameters. We have previously shown [Atabek, et al., Phys. Rev. Lett. 106, 173002 (2011)] how these control parameters, namely, the wavelength and the intensity of the external field, have to be tuned to take advantage of EPs for selective vibrational transfers within a reduced one-dimensional model describing a diatomic molecule with frozen rotation. Moreover, the possibility offered by such transfers to adiabatically transport all the …
Supersymmetry-Generated Complex Optical Potentials With Real Spectra, Mohammad-Ali Miri, Matthias Heinrich, Demetrios N. Christodoulides
Supersymmetry-Generated Complex Optical Potentials With Real Spectra, Mohammad-Ali Miri, Matthias Heinrich, Demetrios N. Christodoulides
Faculty Bibliography 2010s
We show that the formalism of supersymmetry (SUSY), when applied to parity-time (PT) symmetric optical potentials, can give rise to refractive index landscapes with altogether nontrivial properties. In particular, we find that the presence of gain and loss allows for arbitrarily removing bound states from the spectrum of a structure. This is in stark contrast to the Hermitian case, where the SUSY formalism can only address the fundamental mode of a potential. Subsequently we investigate isospectral families of complex potentials that exhibit entirely real spectra, despite the fact that their shapes violate PT symmetry. Finally, the role of SUSY transformations …
Coherent Quantum Transport In Photonic Lattices, Armando Perez-Leija, Robert Keil, Alastair Kay, Hector Moya-Cessa, Stefan Nolte, Leong-Chuan Kwek, Blas M. Rodrìguez-Lara, Alexander Szameit, Demetrios N. Christodoulides
Coherent Quantum Transport In Photonic Lattices, Armando Perez-Leija, Robert Keil, Alastair Kay, Hector Moya-Cessa, Stefan Nolte, Leong-Chuan Kwek, Blas M. Rodrìguez-Lara, Alexander Szameit, Demetrios N. Christodoulides
Faculty Bibliography 2010s
Transferring quantum states efficiently between distant nodes of an information processing circuit is of paramount importance for scalable quantum computing. We report on an observation of a perfect state transfer protocol on a lattice, thereby demonstrating the general concept of transporting arbitrary quantum information with high fidelity. Coherent transfer over 19 sites is realized by utilizing judiciously designed optical structures consisting of evanescently coupled waveguide elements. We provide unequivocal evidence that such an approach is applicable in the quantum regime, for both bosons and fermions, as well as in the classical limit. Our results illustrate the potential of the perfect …
Perfect Transfer Of Path-Entangled Photons In J(X) Photonic Lattices, Armando Perez-Leija, Robert Keil, Hector Moya-Cessa, Alexander Szameit, Demetrios N. Christodoulides
Perfect Transfer Of Path-Entangled Photons In J(X) Photonic Lattices, Armando Perez-Leija, Robert Keil, Hector Moya-Cessa, Alexander Szameit, Demetrios N. Christodoulides
Faculty Bibliography 2010s
We demonstrate that perfect transfer of path-entangled photons as well as of single-photon states is possible in a certain class of spin inspired optical systems-the so-called J(x) photonic lattices. In these fully integrable optical arrangements, perfect cyclic transitions from correlated states to totally anticorrelated states can naturally occur. Moreover we show that the bunching and antibunching response of path-entangled photons can be preengineered at will in such coupled optical arrangements. We elucidate these effects via pertinent examples.
Generating Photon-Encoded W States In Multiport Waveguide-Array Systems, Armando Perez-Leija, J. C. Hernandez-Herrejon, Hector Moya-Cessa, Alexander Szameit, Demetrios N. Christodoulides
Generating Photon-Encoded W States In Multiport Waveguide-Array Systems, Armando Perez-Leija, J. C. Hernandez-Herrejon, Hector Moya-Cessa, Alexander Szameit, Demetrios N. Christodoulides
Faculty Bibliography 2010s
We propose a versatile approach for generating multipartite W states in predesigned on-chip multiport photonic lattices. It is shown that is possible to produce photon-encoded W states where exactly one photon is coherently "shared" among N optical modes by judiciously adjusting the coupling coefficients involved in one-dimensional arrays of evanescently coupled single-mode waveguides. Two-dimensional waveguide configurations are also investigated as possible avenues to produce W states with equal probability amplitudes and equal relative phases.
Extension Of The Multiconfiguration Hartree-Fock Method To Allow Double Photoionization Of Atoms, Hari P. Saha
Extension Of The Multiconfiguration Hartree-Fock Method To Allow Double Photoionization Of Atoms, Hari P. Saha
Faculty Bibliography 2010s
Very recently we were successful in extending the multiconfiguration Hartree-Fock (MCHF) method for electron-impact ionization of atoms to allow double photoionization of atoms. We report, as a test case, the results of our calculation of the triple differential cross section (TDCS) for double photoionization of helium. We have calculated the initial state in the Hartree-Fock and the MCHF approximations and the final state in the Coulomb approximation and the screening potential approximation in order to compare with previously published works. We compare the present results calculated at 30-eV excess photon energy shared equally by two final-state continuum electrons, with other …
Pt-Symmetric Optical Potentials In A Coherent Atomic Medium, Jiteng Sheng, Mohammad-Ali Miri, Demetrios N. Christodoulides, Min Xiao
Pt-Symmetric Optical Potentials In A Coherent Atomic Medium, Jiteng Sheng, Mohammad-Ali Miri, Demetrios N. Christodoulides, Min Xiao
Faculty Bibliography 2010s
We propose that a coherently prepared four-level atomic medium can provide a versatile platform for realizing parity-time (PT) symmetric optical potentials. Different types of PT -symmetric potentials are proposed by appropriately tuning the exciting optical fields and the pertinent atomic parameters. Such reconfigurable and controllable systems may open up new avenues in observing PT -related phenomena with appreciable gain-loss contrast in coherent atomic media.
Supramolecular Step In Design Of Nonlinear Optical Materials: Effect Of Pi ... Pi Stacking Aggregation On Hyperpolarizability, Kyrill Yu Suponitsky, Artëm E. Masunov
Supramolecular Step In Design Of Nonlinear Optical Materials: Effect Of Pi ... Pi Stacking Aggregation On Hyperpolarizability, Kyrill Yu Suponitsky, Artëm E. Masunov
Faculty Bibliography 2010s
Theoretical estimation of nonlinear optical (NLO) properties is an important step in systematic search for optoelectronic materials. Density functional theory methods are often used to predict first molecular hyperpolarizability for compounds in advance of their synthesis. However, design of molecular NLO materials require an estimation of the bulk properties, which are often approximated as additive superposition of molecular tensors. It is therefore important to evaluate the accuracy of this additive approximation and estimate the extent by which intermolecular interactions influence the first molecular hyperpolarizability beta. Here we focused on the stacking aggregates, including up to 12 model molecules (pNA and …
Subcycle Laser Control And Quantum Interferences In Attosecond Photoabsorption Of Neon, Xiaowei Wang, Michael Chini, Yan Cheng, Yi Wu, Xiao-Min Tong, Zenghu Chang
Subcycle Laser Control And Quantum Interferences In Attosecond Photoabsorption Of Neon, Xiaowei Wang, Michael Chini, Yan Cheng, Yi Wu, Xiao-Min Tong, Zenghu Chang
Faculty Bibliography 2010s
The dynamics of an atom in a strong infrared laser field (10(13) W/cm(2)) result in substantial changes to the field-free electronic energy levels, which can be probed on time scales shorter than the laser cycle using isolated attosecond pulses. Here, we measure the transient absorption of an isolated attosecond pulse by laser-dressed bound states of neon near the first ionization threshold. The observed subcycle changes in the absorption spectrum result from both laser-induced ac Stark shifts and from quantum interferences between different multiphoton excitation pathways. We further demonstrate the ability to experimentally turn off the quantum interference mechanism by eliminating …