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.
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.
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 .
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 .
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.
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.
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.
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.
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 .
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 .
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 .
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.
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.
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 .
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 .
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 .
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 .
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 .
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 .
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.
