The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Kejie Fang - One of the best experts on this subject based on the ideXlab platform.
-
non reciprocal phase shift induced by an Effective Magnetic flux for light
Nature Photonics, 2014Co-Authors: Lawrence D Tzuang, Kejie Fang, P Nussenzveig, Michal LipsonAbstract:Photons are neutral particles that do not interact directly with a Magnetic Field. However, recent theoretical work has shown that an Effective Magnetic Field for photons can exist if the phase of light changes with its direction of propagation. This direction-dependent phase indicates the presence of an Effective Magnetic Field, as shown experimentally for electrons in the Aharonov–Bohm experiment. Here, we replicate this experiment using photons. To create this Effective Magnetic Field we construct an on-chip silicon-based Ramsey-type interferometer. This interferometer has been traditionally used to probe the phase of atomic states and here we apply it to probe the phase of photonic states. We experimentally observe an Effective Magnetic flux between 0 and 2π corresponding to a non-reciprocal 2π phase shift with an interferometer length of 8.35 mm and an interference-fringe extinction ratio of 2.4 dB. This non-reciprocal phase is comparable to those of common monolithically integrated magneto-optical materials.
-
observation of an Effective Magnetic Field for light
Conference on Lasers and Electro-Optics, 2014Co-Authors: Lawrence D Tzuang, Kejie Fang, P Nussenzveig, Shanhui Fan, Michal LipsonAbstract:We observe an Effective Magnetic Field for photons using an on-chip silicon-based Ramsey-type interferometer. This interferometer generates a direction-dependent phase which corresponds to a Magnetic Field of 0.2 Gauss in an Aharonov-Bohm configuration for electrons.
-
controlling the flow of light using the inhomogeneous Effective gauge Field that emerges from dynamic modulation
Physical Review Letters, 2013Co-Authors: Kejie FangAbstract:We show that the Effective gauge Field for photons provides a versatile platform for controlling the flow of light. As an example we consider a photonic resonator lattice where the coupling strength between nearest neighbor resonators are harmonically modulated. By choosing different spatial distributions of the modulation phases, and hence imposing different inhomogeneous Effective Magnetic Field configurations, we numerically demonstrate a wide variety of propagation effects including negative refraction, one-way mirror, and on- and off-axis focusing. Since the Effective gauge Field is imposed dynamically after a structure is constructed, our work points to the importance of the temporal degree of freedom for controlling the spatial flow of light.
-
Effective Magnetic Field for photons based on the magneto optical effect
Physical Review A, 2013Co-Authors: Kejie Fang, Shanhui FanAbstract:We propose to create an Effective Magnetic Field for photons in photonic crystal resonator lattices using the magneto-optical effect. The inter-resonator coupling is mediated by magneto-optical waveguides or magneto-optical resonators, and thus the coupling between the nearest-neighbor photonic crystal resonators acquire a direction-dependent phase. The Effective Magnetic Field can be realized with a proper choice of the spatial distribution of such a direction-dependent phase.
-
observation of an Effective Magnetic Field for light
arXiv: Optics, 2013Co-Authors: Lawrence D Tzuang, Kejie Fang, P Nussenzveig, Shanhui Fan, Michal LipsonAbstract:Photons are neutral particles that do not interact directly with a Magnetic Field. However, recent theoretical work has shown that an Effective Magnetic Field for photons can exist if the phase of light would change with its propagating direction. This direction-dependent phase indicates the presence of an Effective Magnetic Field as shown for electrons experimentally in the Aharonov-Bohm experiment. Here we replicate this experiment using photons. In order to create this Effective Magnetic Field, we construct an on-chip silicon-based Ramsey-type interferometer. This interferometer has been traditionally used to probe the phase of atomic states, and here we apply it to probe the phase of photonic states. We experimentally observe a phase change, i.e. an Effective Magnetic Field flux from 0 to 2pi. In an Aharonov-Bohm configuration for electrons, considering the device geometry, this flux corresponds to an Effective Magnetic Field of 0.2 Gauss.
Shanhui Fan - One of the best experts on this subject based on the ideXlab platform.
-
synthetic gauge potential and Effective Magnetic Field in a raman medium undergoing molecular modulation
Physical Review A, 2017Co-Authors: Luqi Yuan, Dawei Wang, Shanhui FanAbstract:We theoretically demonstrate non-trivial topological effects for a probe Field in a Raman medium undergoing molecular modulation processes. The medium is driven by two non-collinear pump beams. We show that the angle between the pumps is related to an Effective gauge potential and an Effective Magnetic Field for the probe Field in the synthetic space consisting of a synthetic frequency dimension and a spatial dimension. As a result of such Effective Magnetic Field, the probe Field can exhibit topologically-protected one-way edge state in the synthetic space, as well as Landau levels which manifests as suppression of both diffraction and sideband generation. Our work identifies a previously unexplored route towards creating topological photonics effects, and highlights an important connection between topological photonics and nonlinear optics.
-
resonator free realization of Effective Magnetic Field for photons
New Journal of Physics, 2015Co-Authors: Qian Lin, Shanhui FanAbstract:We propose to create an Effective Magnetic Field for photons in a two-dimensional waveguide network with strong scattering at waveguide junctions. The Effective Magnetic Field is realized by imposing a direction-dependent phase along each waveguide link. Such a direction-dependent phase can be produced by dynamic modulation or by the magneto-optical effect. Compared to previous proposals for creating an Effective Magnetic Field for photons, this scheme is resonator-free, thus potentially reduces the experimental complexity. We also show that such a waveguide network can be used to explore photonic analogue of integer quantum Hall effect for massless particles.
-
observation of an Effective Magnetic Field for light
Conference on Lasers and Electro-Optics, 2014Co-Authors: Lawrence D Tzuang, Kejie Fang, P Nussenzveig, Shanhui Fan, Michal LipsonAbstract:We observe an Effective Magnetic Field for photons using an on-chip silicon-based Ramsey-type interferometer. This interferometer generates a direction-dependent phase which corresponds to a Magnetic Field of 0.2 Gauss in an Aharonov-Bohm configuration for electrons.
-
Effective Magnetic Field for photons based on the magneto optical effect
Physical Review A, 2013Co-Authors: Kejie Fang, Shanhui FanAbstract:We propose to create an Effective Magnetic Field for photons in photonic crystal resonator lattices using the magneto-optical effect. The inter-resonator coupling is mediated by magneto-optical waveguides or magneto-optical resonators, and thus the coupling between the nearest-neighbor photonic crystal resonators acquire a direction-dependent phase. The Effective Magnetic Field can be realized with a proper choice of the spatial distribution of such a direction-dependent phase.
-
observation of an Effective Magnetic Field for light
arXiv: Optics, 2013Co-Authors: Lawrence D Tzuang, Kejie Fang, P Nussenzveig, Shanhui Fan, Michal LipsonAbstract:Photons are neutral particles that do not interact directly with a Magnetic Field. However, recent theoretical work has shown that an Effective Magnetic Field for photons can exist if the phase of light would change with its propagating direction. This direction-dependent phase indicates the presence of an Effective Magnetic Field as shown for electrons experimentally in the Aharonov-Bohm experiment. Here we replicate this experiment using photons. In order to create this Effective Magnetic Field, we construct an on-chip silicon-based Ramsey-type interferometer. This interferometer has been traditionally used to probe the phase of atomic states, and here we apply it to probe the phase of photonic states. We experimentally observe a phase change, i.e. an Effective Magnetic Field flux from 0 to 2pi. In an Aharonov-Bohm configuration for electrons, considering the device geometry, this flux corresponds to an Effective Magnetic Field of 0.2 Gauss.
Daniel Loss - One of the best experts on this subject based on the ideXlab platform.
-
spin dependent coupling between quantum dots and topological quantum wires
Physical Review B, 2017Co-Authors: Silas Hoffman, Denis Chevallier, Daniel Loss, Jelena KlinovajaAbstract:Considering Rashba quantum wires with a proximity-induced superconducting gap as physical realizations of Majorana fermions and quantum dots, we calculate the overlap of the Majorana wave functions with the local wave functions on the dot. We determine the spin-dependent tunneling amplitudes between these two localized states and show that we can tune into a fully spin polarized tunneling regime by changing the distance between dot and Majorana fermion. Upon directly applying this to the tunneling model Hamiltonian, we calculate the Effective Magnetic Field on the quantum dot flanked by two Majorana fermions. The direction of the induced Magnetic Field on the dot depends on the occupation of the nonlocal fermion formed from the two Majorana end states which can be used as a readout for such a Majorana qubit.
-
electric dipole induced spin resonance in quantum dots
Physical Review B, 2006Co-Authors: Vitaly N Golovach, Massoud Borhani, Daniel LossAbstract:An alternating electric Field, applied to a quantum dot, couples to the electron spin via the spin-orbit interaction. We analyze different types of spin-orbit coupling known in the literature and find two efficient mechanisms of spin control in quantum dots. The linear in momentum Dresselhaus and Rashba spin-orbit couplings give rise to a fully transverse Effective Magnetic Field in the presence of a Zeeman splitting at lowest order in the spin-orbit interaction. The cubic in momentum Dresselhaus terms are efficient in a quantum dot with anharmonic confining potential and give rise to a spin-electric coupling proportional to the orbital Magnetic Field. We derive an Effective spin Hamiltonian, which can be used to implement spin manipulation on a time scale of 10 ns with the current experimental setups.
D D Solnyshkov - One of the best experts on this subject based on the ideXlab platform.
-
all optical controlled not gate based on an exciton polariton circuit
Superlattices and Microstructures, 2015Co-Authors: D D Solnyshkov, O Bleu, G MalpuechAbstract:Abstract We propose an implementation of a CNOT gate for quantum computing based on a patterned microcavity polariton system, which can be manufactured using the modern technological facilities. The qubits are encoded in the spin-coherent polariton states. The structure consists of two wire cavities oriented at 45° with a micropillar between them. The polariton spin rotates due to the Longitudinal–Transverse splitting between polarization eigenstates in the wires. In the pillar, the optically generated circularly polarized polariton macrooccupied state plays the role of the control qubit. Because of the spin-anisotropic polariton interaction, it induces an Effective Magnetic Field along the Z-direction with a sign depending on the qubit value.
-
spin orbit coupling and the optical spin hall effect in photonic graphene
Physical Review Letters, 2015Co-Authors: A V Nalitov, G Malpuech, H Tercas, D D SolnyshkovAbstract:We study the spin-orbit coupling induced by the splitting between TE and TM optical modes in a photonic honeycomb lattice. Using a tight-binding approach, we calculate analytically the band structure. Close to the Dirac point, we derive an Effective Hamiltonian. We find that the local reduced symmetry (D_{3h}) transforms the TE-TM Effective Magnetic Field into an emergent Field with a Dresselhaus symmetry. As a result, particles become massive, but no gap opens. The emergent Field symmetry is revealed by the optical spin Hall effect.
Patrik Ohberg - One of the best experts on this subject based on the ideXlab platform.
-
elementary excitations of a bose einstein condensate in an Effective Magnetic Field
Physical Review A, 2007Co-Authors: D R Murray, Patrik Ohberg, Stephen M Barnett, Damia GomilaAbstract:We calculate the low-energy elementary excitations of a Bose-Einstein condensate in an Effective Magnetic Field. The Field is created by the interplay between light beams carrying orbital angular momentum and the trapped atoms [G. Juzelinas et al., Phys. Rev. A 71, 053614 (2005)]. We examine the role of the homogeneous Magnetic Field, familiar from studies of rotating condensates, and also investigate spectra for vector potentials with a more general radial dependence. We discuss the instabilities which arise and how these may be manifested.
-
filled landau levels in neutral quantum gases
Physical Review A, 2005Co-Authors: Patrik Ohberg, J Ruseckas, G Juzelinas, Michael FleischhauerAbstract:We consider the signatures of the integer quantum Hall effect in a degenerate gas of electrically neutral atomic fermions. An Effective Magnetic Field is achieved by applying two incident light beams with a high orbital angular momentum. We show how states corresponding to completely filled Landau levels are obtained and discuss various possibilities to measure the incompressible nature of the trapped two-dimensional gas.
-
Effective Magnetic Fields in degenerate atomic gases induced by light beams with orbital angular momenta
Physical Review A, 2005Co-Authors: Gediminas Juzeliunas, Patrik Ohberg, J Ruseckas, A KleinAbstract:We investigate the influence of two resonant laser beams on the mechanical properties of degenerate atomic gases. The control and probe beams of light are considered to have orbital angular momenta (OAM) and act on the three-level atoms in the electroMagnetically induced transparency configuration. The theory is based on the explicit analysis of the quantum dynamics of cold atoms coupled with two laser beams. Using the adiabatic approximation, we obtain an Effective equation of motion for the atoms driven to the dark state. The equation contains a vector-potential-type interaction as well as an Effective trapping potential. The Effective Magnetic Field is shown to be oriented along the propagation direction of the control and probe beams containing OAM. Its spatial profile can be controlled by choosing proper laser beams. We demonstrate how to generate a constant Effective Magnetic Field, as well as a Field exhibiting a radial distance dependence. The resulting Effective Magnetic Field can be concentrated within a region where the Effective trapping potential holds the atoms. The estimated Magnetic length can be considerably smaller than the size of the atomic cloud.