Virtual Journal of Quantum Information
Photonic analogue of Josephson effect in a dual-species optical-lattice cavity
Soi-Chan Lei, Tai-Kai Ng, and Ray-Kuang Lee
We extend the idea of quantum phase transitions of light in the photonic Bose-Hubbard model with interactions to two atomic species by a self-consistent mean field theory. The excitation of two-level atoms interacting with a coherent photon field is analyzed with a finite temperature dependence of t ... [Opt. Express 18, 14586 (2010)] published Thu Aug 5, 2010.
We extend the idea of quantum phase transitions of light in the photonic Bose-Hubbard model with interactions to two atomic species by a self-consistent mean field theory. The excitation of two-level atoms interacting with a coherent photon field is analyzed with a finite temperature dependence of t ... [Opt. Express 18, 14586 (2010)] published Thu Aug 5, 2010.
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Switching of a single propagating plasmon by two quantum dots system
Nam-Chol Kim, Jian-Bo Li, Zhong-Jian Yang, Zhong-Hua Hao, and Qu-Quan Wang
We investigated the scattering property of a single plasmon interacting with two quantum dots coupled to one-dimensional surface plasmonic waveguide. We demonstrated that the transmission of a single plasmon could be switched on or off by adjusting spectral detuning and controlling spatial separatio ... [Appl. Phys. Lett. 97, 061110 (2010)] published Thu Aug 12, 2010.
We investigated the scattering property of a single plasmon interacting with two quantum dots coupled to one-dimensional surface plasmonic waveguide. We demonstrated that the transmission of a single plasmon could be switched on or off by adjusting spectral detuning and controlling spatial separatio ... [Appl. Phys. Lett. 97, 061110 (2010)] published Thu Aug 12, 2010.
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Dynamically reconfigurable directionality of plasmon-based single photon sources
Yuntian Chen, Peter Lodahl, and A. Femius Koenderink
We propose a plasmon-based reconfigurable antenna to controllably distribute emission from single quantum emitters in spatially separated channels. Our calculations show that crossed particle arrays can split the stream of photons from a single emitter into multiple narrow beams. We predict that bea ... [Phys. Rev. B 82, 081402 ] published .
We propose a plasmon-based reconfigurable antenna to controllably distribute emission from single quantum emitters in spatially separated channels. Our calculations show that crossed particle arrays can split the stream of photons from a single emitter into multiple narrow beams. We predict that bea ... [Phys. Rev. B 82, 081402 ] published .
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Electron Spin Coherence and Electron Nuclear Double Resonance of Bi Donors in Natural Si
Richard E. George, Wayne Witzel, H. Riemann, N. V. Abrosimov, N. Notzel et al.
Donors in silicon hold considerable promise for emerging quantum technologies, due to their uniquely long electron spin coherence times. Bismuth donors in silicon differ from more widely studied group V donors, such as phosphorous, in several significant respects: They have the strongest binding ene ... [Phys. Rev. Lett. 105, 067601 ] published .
Donors in silicon hold considerable promise for emerging quantum technologies, due to their uniquely long electron spin coherence times. Bismuth donors in silicon differ from more widely studied group V donors, such as phosphorous, in several significant respects: They have the strongest binding ene ... [Phys. Rev. Lett. 105, 067601 ] published .
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Efficient photon number detection with silicon avalanche photodiodes
O. Thomas, Z. L. Yuan, J. F. Dynes, A. W. Sharpe, and A. J. Shields
We demonstrate an efficient photon number detector for visible wavelengths using a silicon avalanche photodiode. Under subnanosecond gating, the device is able to resolve up to four photons in an incident optical pulse. The detection efficiency at 600 nm is measured to be 73.8%, corresponding to an ... [Appl. Phys. Lett. 97, 031102 (2010)] published Mon Jul 19, 2010.
We demonstrate an efficient photon number detector for visible wavelengths using a silicon avalanche photodiode. Under subnanosecond gating, the device is able to resolve up to four photons in an incident optical pulse. The detection efficiency at 600 nm is measured to be 73.8%, corresponding to an ... [Appl. Phys. Lett. 97, 031102 (2010)] published Mon Jul 19, 2010.
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Differential reflection spectroscopy of a single quantum dot strongly coupled to a photonic crystal cavity
Erik D. Kim, Arka Majumdar, Hyochul Kim, Pierre Petroff, and Jelena VuCkovic
We demonstrate the use of periodically modulated Coulomb shifts in quantum dot (QD) transition energies to obtain differential reflection spectra of a photonic crystal nanocavity containing strongly coupled dots. Measured spectra isolate the change in the empty cavity optical reflectivity spectrum d ... [Appl. Phys. Lett. 97, 053111 (2010)] published Wed Aug 4, 2010.
We demonstrate the use of periodically modulated Coulomb shifts in quantum dot (QD) transition energies to obtain differential reflection spectra of a photonic crystal nanocavity containing strongly coupled dots. Measured spectra isolate the change in the empty cavity optical reflectivity spectrum d ... [Appl. Phys. Lett. 97, 053111 (2010)] published Wed Aug 4, 2010.
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Fabrication of concave silicon micro-mirrors
Yueh Sheng Ow, Mark B. H. Breese, and Sara Azimi
We have fabricated spherical and cylindrical concave micro-mirrors in silicon with dimensions from 20 [mu]m to 100 [mu]m. The fabrication process involves standard photolithography followed by large area ion beam irradiation and electrochemical anodisation in a HF electrolyte. After thermal oxidatio ... [Opt. Express 18, 14511 (2010)] published Thu Aug 5, 2010.
We have fabricated spherical and cylindrical concave micro-mirrors in silicon with dimensions from 20 [mu]m to 100 [mu]m. The fabrication process involves standard photolithography followed by large area ion beam irradiation and electrochemical anodisation in a HF electrolyte. After thermal oxidatio ... [Opt. Express 18, 14511 (2010)] published Thu Aug 5, 2010.
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Measurement of the effect of quantum phase slips in a Josephson junction chain
I. M. Pop, I. Protopopov, F. Lecocq, Z. Peng, B. Pannetier et al.
The interplay between superconductivity and Coulomb interactions has been studied for more than 20 years now. In low-dimensional systems, superconductivity degrades in the presence of Coulomb repulsion: interactions tend to suppress fluctuations of charge, thereby increasing fluctuations of phase. ... [Nature Phys. 6, 589 (2010)] published Wed Aug 4, 2010.
The interplay between superconductivity and Coulomb interactions has been studied for more than 20 years now. In low-dimensional systems, superconductivity degrades in the presence of Coulomb repulsion: interactions tend to suppress fluctuations of charge, thereby increasing fluctuations of phase. ... [Nature Phys. 6, 589 (2010)] published Wed Aug 4, 2010.
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Effect of Mechanical Strain on the Optical Properties of Quantum Dots: Controlling Exciton Shape, Orientation, and Phase with a Mechanical Strain
Garnett W. Bryant, M. Zielinski, Natalia Malkova, James Sims, W. Jaskolski et al.
We show how a nanomechanical strain can be used to dynamically reengineer the optics of quantum dots, giving a tool to manipulate mechanoexciton shape, orientation, fine structure splitting, and optical transitions, transfer carriers between dots, and interact qubits for quantum processing. Most imp ... [Phys. Rev. Lett. 105, 067404 ] published .
We show how a nanomechanical strain can be used to dynamically reengineer the optics of quantum dots, giving a tool to manipulate mechanoexciton shape, orientation, fine structure splitting, and optical transitions, transfer carriers between dots, and interact qubits for quantum processing. Most imp ... [Phys. Rev. Lett. 105, 067404 ] published .
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Improving Quantum State Estimation with Mutually Unbiased Bases
R. B. A. Adamson and A. M. Steinberg
When used in quantum state estimation, projections onto mutually unbiased bases have the ability to maximize information extraction per measurement and to minimize redundancy. We present the first experimental demonstration of quantum state tomography of two-qubit polarization states to take advanta ... [Phys. Rev. Lett. 105, 030406 ] published .
When used in quantum state estimation, projections onto mutually unbiased bases have the ability to maximize information extraction per measurement and to minimize redundancy. We present the first experimental demonstration of quantum state tomography of two-qubit polarization states to take advanta ... [Phys. Rev. Lett. 105, 030406 ] published .
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Efficient multimode quantum memory based on photon echo in an optimal QED cavity
Sergey A. Moiseev, Sergey N. Andrianov, and Firdus F. Gubaidullin
Effective multimode photon echo quantum memory on multiatomic ensemble in the QED cavity is proposed. We obtain the analytical solution for the quantum memory efficiency that can be equal to unity when optimal conditions for the cavity and atomic parameters are held. Detailed analysis of the optimal ... [Phys. Rev. A 82, 022311 ] published .
Effective multimode photon echo quantum memory on multiatomic ensemble in the QED cavity is proposed. We obtain the analytical solution for the quantum memory efficiency that can be equal to unity when optimal conditions for the cavity and atomic parameters are held. Detailed analysis of the optimal ... [Phys. Rev. A 82, 022311 ] published .
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High efficient loading of two atoms into a microscopic optical trap by dynamically reshaping the trap with a spatial light modulator
Xiaodong He, Peng Xu, Jin Wang, and Mingsheng Zhan
We demonstrated trapping two neutral Rb atoms in a two site optical ring lattice generated by reflecting a single laser beam from a computer controlled spatial light modulator directly. The ring lattice was transformed into a Gaussian trap by dynamically displaying the holograms animation movi ... [Opt. Express 18, 13586 (2010)] published Thu Aug 5, 2010.
We demonstrated trapping two neutral Rb atoms in a two site optical ring lattice generated by reflecting a single laser beam from a computer controlled spatial light modulator directly. The ring lattice was transformed into a Gaussian trap by dynamically displaying the holograms animation movi ... [Opt. Express 18, 13586 (2010)] published Thu Aug 5, 2010.
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Coherent control of a single exciton qubit by optoelectronic manipulation
S. Michaelis de Vasconcellos, S. Gordon, M. Bichler, T. Meier, and A. Zrenner
The coherent state manipulation of single quantum systems is a fundamental requirement for the implementation of quantum information processors. Exciton qubits are of particular interest for coherent optoelectronic applications, in particular due to their excellent coupling to photons. Until now, co ... [Nat. Photonics 4, 545 (2010)] published Wed Aug 4, 2010.
The coherent state manipulation of single quantum systems is a fundamental requirement for the implementation of quantum information processors. Exciton qubits are of particular interest for coherent optoelectronic applications, in particular due to their excellent coupling to photons. Until now, co ... [Nat. Photonics 4, 545 (2010)] published Wed Aug 4, 2010.
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Bootstrap Tomography of the Pulses for Quantum Control
V. V. Dobrovitski, G. de Lange, D. Riste, and R. Hanson
Long-time dynamical decoupling and quantum control of qubits require high-precision control pulses. Full characterization (quantum tomography) of imperfect pulses presents a bootstrap problem: tomography requires initial states of a qubit which cannot be prepared without perfect pulses. We present a ... [Phys. Rev. Lett. 105, 077601 ] published .
Long-time dynamical decoupling and quantum control of qubits require high-precision control pulses. Full characterization (quantum tomography) of imperfect pulses presents a bootstrap problem: tomography requires initial states of a qubit which cannot be prepared without perfect pulses. We present a ... [Phys. Rev. Lett. 105, 077601 ] published .
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Three-dimensional transport diagram of a triple quantum dot
G. Granger, L. Gaudreau, A. Kam, M. Pioro-Ladriere, S. A. Studenikin et al.
We measure a triple quantum dot in the regime where three addition lines, corresponding to the addition of an electron to each of three dots, pass through each other. In particular, we probe the interplay between transport and the three-dimensional nature of the stability diagram. We choose the regi ... [Phys. Rev. B 82, 075304 ] published .
We measure a triple quantum dot in the regime where three addition lines, corresponding to the addition of an electron to each of three dots, pass through each other. In particular, we probe the interplay between transport and the three-dimensional nature of the stability diagram. We choose the regi ... [Phys. Rev. B 82, 075304 ] published .
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Quantum theory of surface-plasmon polariton scattering
D. Ballester, M. S. Tame, and M. S. Kim
We introduce the quantum mechanical formalism for treating surface plasmon polariton scattering at an interface. Our developed theorywhich differs fundamentally from the analogous photonic scenariois used to investigate the possibility of plasmonic beam splitters at the quantum level. Remarkably, we ... [Phys. Rev. A 82, 012325 ] published .
We introduce the quantum mechanical formalism for treating surface plasmon polariton scattering at an interface. Our developed theorywhich differs fundamentally from the analogous photonic scenariois used to investigate the possibility of plasmonic beam splitters at the quantum level. Remarkably, we ... [Phys. Rev. A 82, 012325 ] published .
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Spin-orbit coupling and anisotropic exchange in two-electron double quantum dots
Fabio Baruffa, Peter Stano, and Jaroslav Fabian
The influence of the spin-orbit interactions on the energy spectrum of two-electron laterally coupled quantum dots is investigated. The effective Hamiltonian for a spin qubit pair proposed in Baruffa et al. [Phys. Rev. Lett. 104, 126401 (2010)] is confronted with exact numerical results in single an ... [Phys. Rev. B 82, 045311 ] published .
The influence of the spin-orbit interactions on the energy spectrum of two-electron laterally coupled quantum dots is investigated. The effective Hamiltonian for a spin qubit pair proposed in Baruffa et al. [Phys. Rev. Lett. 104, 126401 (2010)] is confronted with exact numerical results in single an ... [Phys. Rev. B 82, 045311 ] published .
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Fluorescence interferometry
G. S. Paraoanu
We describe an interferometer based on fluorescent emission of radiation of two qubits in quasi-one-dimensional modes. Such a system can readily be realized with dipole emitters near conducting surface-plasmonic nanowires or with superconducting qubits coupled to coplanar waveguide transmission line ... [Phys. Rev. A 82, 023802 ] published .
We describe an interferometer based on fluorescent emission of radiation of two qubits in quasi-one-dimensional modes. Such a system can readily be realized with dipole emitters near conducting surface-plasmonic nanowires or with superconducting qubits coupled to coplanar waveguide transmission line ... [Phys. Rev. A 82, 023802 ] published .
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Transition from weak to strong measurements by nonlinear quantum feedback control
Jing Zhang, Yu-xi Liu, Re-Bing Wu, Chun-Wen Li, and Tzyh-Jong Tarn
We find that feedback control may induce pseudo-nonlinear dynamics in a damped harmonic oscillator, whose centroid trajectory in the phase space behaves like a classical nonlinear system. Thus, similar to nonlinear amplifiers (e.g., rf-driven Josephson junctions), feedback control on the harmonic os ... [Phys. Rev. A 82, 022101 ] published .
We find that feedback control may induce pseudo-nonlinear dynamics in a damped harmonic oscillator, whose centroid trajectory in the phase space behaves like a classical nonlinear system. Thus, similar to nonlinear amplifiers (e.g., rf-driven Josephson junctions), feedback control on the harmonic os ... [Phys. Rev. A 82, 022101 ] published .
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Implementation of superconductor/ferromagnet/ superconductor -shifters in superconducting digital and quantum circuits
A. K. Feofanov, V. A. Oboznov, V. V. Bolginov, J. Lisenfeld, S. Poletto et al.
High operation speed and low energy consumption may allow the superconducting digital single-flux-quantum circuits to outperform traditional complementary metaloxidesemiconductor logic. The remaining major obstacle towards high element densities on-chip is a relatively large cell size necessary to ... [Nature Phys. 6, 593 (2010)] published Wed Aug 4, 2010.
High operation speed and low energy consumption may allow the superconducting digital single-flux-quantum circuits to outperform traditional complementary metaloxidesemiconductor logic. The remaining major obstacle towards high element densities on-chip is a relatively large cell size necessary to ... [Nature Phys. 6, 593 (2010)] published Wed Aug 4, 2010.
Categories: Journals
