Searched for: department%3A%22Quantum%255C+Nanoscience%22
(401 - 420 of 461)

Pages

document
De Visser, P.J. (author), Baselmans, J.J.A. (author), Diener, P. (author), Yates, S.J.C. (author), Endo, A. (author), Klapwijk, T.M. (author)
We have directly measured quasiparticle number fluctuations in a thin film superconducting Al resonator in thermal equilibrium. The spectrum of these fluctuations provides a measure of both the density and the lifetime of the quasiparticles. We observe that the quasiparticle density decreases exponentially with decreasing temperature, as...
journal article 2011
document
Dorenbos, S.N. (author), Zwiller, V.G. (author), Schouten, R.N. (author)
Detection arrangement having an array of at least one superconducting single photon detector (SSPD). The detection arrangement further has a cryogenic part (9) with the array of at least one SSPD (1), the cryogenic part (9) being at a superconducting temperature in operation. Also, a separate charge storage element (5) in the form of an...
patent 2011
document
Kovalev, A.A. (author), Hayden, L.X. (author), Bauer, G.E.W. (author), Tserkovnyak, Y. (author)
We theoretically address the quantum dynamics of a nanomechanical resonator coupled to the macrospin of a magnetic nanoparticle by both instanton and perturbative approaches. We demonstrate suppression of the tunneling between opposite magnetizations and destruction of magnetopolaritons (coherent magnetomechanical oscillations) by nanomechanical...
journal article 2011
document
Chen, T. (author), Wu, M.Y. (author), Ishihara, R. (author), Nomura, K. (author), Kamiya, T. (author), Hosono, H. (author), Beenakker, C.I.M. (author)
In this paper, we were able to crystallize InGaZnO4 (IGZO) by excimer laser on SiO2 substrate. It was observed that uniform [0001] textured polycrystalline IGZO film has been obtained without any grain boundaries and oxygen vacancies on SiO2 substrate. This process is very promising in fabricating high quality IGZO thin film transistors (TFT) at...
journal article 2011
document
Cui, M. (author), Zeitouny, M.G. (author), Bhattacharya, N. (author), Van den Berg, S.A. (author), Urbach, H.P. (author)
We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an...
journal article 2011
document
Xiong, C. (author), Marshall, G.D. (author), Peruzzo, A. (author), Lobino, M. (author), Clark, A.S. (author), Choi, D.Y. (author), Madden, S.J. (author), Natarajan, C.M. (author), Tanner, M.G. (author), Hadfield, R.H. (author), Dorenbos, S.N. (author), Zijlstra, T. (author), Zwiller, V. (author), Thompson, M.G. (author), Rarity, J.G. (author), Steel, M.J. (author), Luther-Davies, B. (author), Eggleton, B.J. (author), O'Brien, J.L. (author)
journal article 2011
document
Meunier, T. (author), Calado, V.E. (author), Vandersypen, L.M.K. (author)
Two-qubit interactions are at the heart of quantum information processing. For single-spin qubits in semiconductor quantum dots, the exchange gate has always been considered the natural two-qubit gate. The recent integration of a magnetic field or g-factor gradients in coupled quantum dot systems allows for a one-step, robust realization of the...
journal article 2011
document
Marsili, F. (author), Najafi, F. (author), Herder, C. (author), Berggren, K.K. (author)
We developed an electrothermal model of NbN superconducting nanowire avalanche photodetectors (SNAPs) on sapphire substrates. SNAPs are single-photon detectors consisting of the parallel connection of N superconducting nanowires. We extrapolated the physical constants of the model from experimental data and we simulated the time evolution of the...
journal article 2011
document
De Lange, G. (author), Ristè, D. (author), Dobrovitski, V.V. (author), Hanson, R. (author)
We experimentally demonstrate single-spin magnetometry with multipulse sensing sequences. The use of multipulse sequences can greatly increase the sensing time per measurement shot, resulting in enhanced ac magnetic field sensitivity. We theoretically derive and experimentally verify the optimal number of sensing cycles, for which the effects of...
journal article 2011
document
Bandopadyay, S. (author), Brataas, A. (author), Bauer, G.E.W. (author)
The miniaturization of magnetic read heads and random access memory elements makes them vulnerable to thermal fluctuations. We demonstrate how current-induced spin-transfer torques can be used to suppress the effects of thermal fluctuations. This enhances the fidelity of perpendicular magnetic spin valves. The simplest realization is a dc to...
journal article 2011
document
Perinetti, U. (author)
This thesis presents different optical experiments performed on semiconductor quantum dots. These structures allow to confine a small number of electrons and holes to a tiny region of space, some nm across. The aim of this work was to study the basic properties of different types of quantum dots made of various materials and with different...
doctoral thesis 2011
document
Hriscu, A.M. (author), Nazarov, Y.V. (author)
We theoretically investigate a driven oscillator with the superconducting inductance subject to quantum phase slips (QPS). We find uncommon nonlinearities in the proposed device: they oscillate as a function of the number of photons N with a local period of the order of ?N. We prove that such nonlinearities result in multiple metastable states...
journal article 2011
document
Xiong, C. (author), Marshall, G.D. (author), Peruzzo, A. (author), Lobino, M. (author), Clark, A.S. (author), Choi, D.Y. (author), Madden, S.J. (author), Natarajan, C.M. (author), Tanner, M.G. (author), Hadfield, R.H. (author), Dorenbos, S.N. (author), Zijlstra, T. (author), Zwiller, V. (author), Thompson, M.G. (author), Rarity, J.G. (author), Steel, M.J. (author), Luther-Davies, B. (author), Eggleton, B.J. (author), O'Brien, J.L. (author)
We demonstrate a 1550 nm correlated photon-pair source in an integrated glass platform—a chalcogenide As2S3 waveguide. A measured pair coincidence rate of 80?s?1 was achieved using 57 mW of continuous-wave pump. The coincidence to accidental ratio was shown to be limited by spontaneous Raman scattering effects that are expected to be mitigated...
journal article 2011
document
Medvedyeva, M.V. (author), Blanter, Y.M. (author)
We investigate the conductivity of graphene sheet deformed over a gate. The effect of the deformation on the conductivity is twofold: The lattice distortion can be represented as pseudovector potential in the Dirac equation formalism, whereas the gate causes inhomogeneous density redistribution. We use the elasticity theory to find the profile...
journal article 2011
document
Bakkers, E.P.A.M. (author)
public lecture 2011
document
Mirjani, F. (author), Thijssen, J.M. (author)
We present a method which uses density functional theory (DFT) to treat transport through a single molecule connected to two conducting leads for the weak and intermediate coupling. This case is not accessible to standard nonequilibrium Green’s function calculations. Our method is based on a mapping of the Hamiltonian on the molecule to a...
journal article 2011
document
Walker, C. (author), Kulesa, C. (author), Gao, J.R. (author)
In the wavelength regime between 60 and 300 microns there are a number of atomic and molecular emission lines that are key diagnostic probes of the interstellar medium. These include transitions of [CII], [NII], [OI], HD, H2D+, OH, CO, and H2O, some of which are among the brightest global and local far-infrared lines in the Galaxy. In Giant...
journal article 2010
document
Johnson, B.C. (author), Tettamanzi, G.C. (author), Yang, C. (author), Alves, A.D.C. (author), Van Donkelaar, J. (author), Thompson, S. (author), Verduijn, J. (author), Mol, J.A. (author), Wacquez, R. (author), Vinet, M. (author), Dzurak, A.S. (author), Sanquer, M. (author), Rogge, S. (author), Jamieson, D.N. (author)
Deterministic doping is crucial for overcoming dopant number variability in present nano-scale devices and for exploiting single atom degrees of freedom. The development of determinisitic doping schemes is required. Here, two approaches to the detection of single ion impact events in Si-based devices are reviewed. The first is via specialized...
journal article 2010
document
Tiwari, R.P. (author), Blaauboer, M. (author)
We consider quantum pumping of Dirac fermions in a monolayer of graphene in the presence of a perpendicular magnetic field in the central pumping region. The two external pump parameters are electrical voltages applied to the graphene sheet on either side of the pumping region. We analyze this pump within scattering matrix formalism and...
journal article 2010
document
Didier, N. (author), Blanter, Y.M. (author), Hekking, F.W.J. (author)
Recently, a lasing effect has been observed in a superconducting nanocircuit where a Cooper-pair box, acting as an artificial three-level atom, was coupled to a resonator [O. Astafiev, K. Inomata, A. O. Niskanen, T. Yamamoto, Yu. A. Pashkin, Y. Nakamura, and J. S. Tsai, Nature (London) 449, 588 (2007)]. Motivated by this experiment, we analyze...
journal article 2010
Searched for: department%3A%22Quantum%255C+Nanoscience%22
(401 - 420 of 461)

Pages