Magnetic field tuning of coplanar waveguide resonators

We describe measurements on microwave coplanar resonators designed for quantum bit experiments. Resonators have been patterned onto sapphire and silicon substrates, and quality factors in excess of a million have been observed. The resonant frequency shows a high sensitivity to magnetic field applied perpendicular to the plane of the film, with a quadratic dependence for the fundamental, second and third harmonics. Frequency shift of hundreds of linewidths can be obtained.Comment: Accepted for publication in AP

On the properties of superconducting planar resonators at mK temperatures

Planar superconducting resonators are now being increasingly used at mK temperatures in a number of novel applications. They are also interesting devices in their own right since they allow us to probe the properties of both the superconductor and its environment. We have experimentally investigated three types of niobium resonators - including a lumped element design - fabricated on sapphire and SiO_2/Si substrates. They all exhibit a non-trivial temperature dependence of their centre frequency and quality factor. Our results shed new light on the interaction between the electromagnetic waves in the resonator and two-level fluctuators in the substrate.Comment: V2 includes some minor corrections/changes. Submitted to PR

Circuit QED with a Flux Qubit Strongly Coupled to a Coplanar Transmission Line Resonator

We propose a scheme for circuit quantum electrodynamics with a superconducting flux-qubit coupled to a high-Q coplanar resonator. Assuming realistic circuit parameters we predict that it is possible to reach the strong coupling regime. Routes to metrological applications, such as single photon generation and quantum non-demolition measurements are discussed.Comment: 8 pages, 5 figure

Anatomy of the long head of biceps femoris: An ultrasound study

Hamstring strains, particularly involving the long head of biceps femoris (BFlh) at the proximal musculotendinous junction (MTJ), are commonly experienced by athletes. With the use of diagnostic ultrasound increasing, an in-depth knowledge of normal ultrasonographic anatomy is fundamental to better understanding hamstring strain. The aim of this study was to describe the architecture of BFlh, using ultrasonography, in young men and cadaver specimens. BFlh morphology was examined in 19 healthy male participants (mean age 21.6 years) using ultrasound. Muscle, tendon and MTJ lengths were recorded and architectural parameters assessed at four standardised points along the muscle. Measurement accuracy was validated by ultrasound and dissection of BFlh in six male cadaver lower limbs (mean age 76 years). Intra-rater reliability of architectural parameters was examined for repeat scans, image analysis and dissection measurements. Distally the BFlh muscle had significantly (P

Quantum Dynamics of a Bose Superfluid Vortex

We derive a fully quantum-mechanical equation of motion for a vortex in a 2-dimensional Bose superfluid, in the temperature regime where the normal fluid density $\rho_n(T)$ is small. The coupling between the vortex "zero mode" and the quasiparticles has no term linear in the quasiparticle variables -- the lowest-order coupling is quadratic. We find that as a function of the dimensionless frequency $\tilde \Omega = \hbar \Omega/k_BT$, the standard Hall-Vinen/Iordanskii equations are valid when $\tilde \Omega \ll 1$ (the "classical regime"), but elsewhere, the equations of motion become highly retarded, with significant experimental implications when $\tilde \Omega \gtrsim 1$.Comment: 12 pages (4 pages + supp info), 2 figures, accepted to PR

Gap Probabilities for Edge Intervals in Finite Gaussian and Jacobi Unitary Matrix Ensembles

The probabilities for gaps in the eigenvalue spectrum of the finite dimension $N \times N$ random matrix Hermite and Jacobi unitary ensembles on some single and disconnected double intervals are found. These are cases where a reflection symmetry exists and the probability factors into two other related probabilities, defined on single intervals. Our investigation uses the system of partial differential equations arising from the Fredholm determinant expression for the gap probability and the differential-recurrence equations satisfied by Hermite and Jacobi orthogonal polynomials. In our study we find second and third order nonlinear ordinary differential equations defining the probabilities in the general $N$ case. For N=1 and N=2 the probabilities and thus the solution of the equations are given explicitly. An asymptotic expansion for large gap size is obtained from the equation in the Hermite case, and also studied is the scaling at the edge of the Hermite spectrum as $N \to \infty$, and the Jacobi to Hermite limit; these last two studies make correspondence to other cases reported here or known previously. Moreover, the differential equation arising in the Hermite ensemble is solved in terms of an explicit rational function of a {Painlev\'e-V} transcendent and its derivative, and an analogous solution is provided in the two Jacobi cases but this time involving a {Painlev\'e-VI} transcendent.Comment: 32 pages, Latex2

Properties of nonaqueous electrolytes Sixth summary report, 20 Sep. 1967 - 19 Mar. 1968

Physical properties and structural studies on propylene carbonate, dimethyl formamide, and acetonitrile solvent electrolyte

Universality for orthogonal and symplectic Laguerre-type ensembles

We give a proof of the Universality Conjecture for orthogonal (beta=1) and symplectic (beta=4) random matrix ensembles of Laguerre-type in the bulk of the spectrum as well as at the hard and soft spectral edges. Our results are stated precisely in the Introduction (Theorems 1.1, 1.4, 1.6 and Corollaries 1.2, 1.5, 1.7). They concern the appropriately rescaled kernels K_{n,beta}, correlation and cluster functions, gap probabilities and the distributions of the largest and smallest eigenvalues. Corresponding results for unitary (beta=2) Laguerre-type ensembles have been proved by the fourth author in [23]. The varying weight case at the hard spectral edge was analyzed in [13] for beta=2: In this paper we do not consider varying weights. Our proof follows closely the work of the first two authors who showed in [7], [8] analogous results for Hermite-type ensembles. As in [7], [8] we use the version of the orthogonal polynomial method presented in [25], [22] to analyze the local eigenvalue statistics. The necessary asymptotic information on the Laguerre-type orthogonal polynomials is taken from [23].Comment: 75 page

Personalised digital interventions for reducing hazardous and harmful alcohol consumption in community-dwelling populations

This is the protocol for a review and there is no abstract. The objectives are as follows: The main objective is to assess the effectiveness and cost effectiveness of digital interventions for reducing hazardous and harmful alcohol consumption and/or alcohol-related problems in community-dwelling populations. We envisage two comparator groups: (1) no intervention (or minimal input) controls; and (2) another active intervention for delivering preventive advice or counselling to reduce hazardous or harmful alcohol consumption. Specifically, we will address two questions: (1) Are digital interventions superior to no intervention (or minimal input) controls? This question is important for individuals accessing interventions through their own motivation or interest. These individuals will be unlikely to experience active practitioner input and it is important to understand whether digital interventions are better than general material they might seek out on the internet or via mobile phone-based apps etc. (2) Are digital interventions at least equally effective as face-to-face brief alcohol interventions? Practitioner delivered brief interventions are generally accepted to be the best alternative in secondary preventive care in health, workplace, educational or community settings. However, time constraints can impede face-to-face delivery of such interventions and it is important to know whether digitally provided input can yield comparable effects to interventions delivered by trained practitioners. We will also identify the most effective component behaviour change techniques of such interventions and their mechanisms of action. Secondary objectives are as follows: 1.To assess whether outcomes differ between trials where the digital intervention targets participants attending health, social care, education or other community-based settings and those where it is offered remotely via the internet or mobile phone platforms; 2.To develop a taxonomy of interventions according to their mode of delivery (e.g. functionality features) and assess their impact on outcomes; 3.To identify theories or models that have been used in the development and/or evaluation of the intervention – this will inform intervention development work

The Calogero-Moser equation system and the ensemble average in the Gaussian ensembles

From random matrix theory it is known that for special values of the coupling constant the Calogero-Moser (CM) equation system is nothing but the radial part of a generalized harmonic oscillator Schroedinger equation. This allows an immediate construction of the solutions by means of a Rodriguez relation. The results are easily generalized to arbitrary values of the coupling constant. By this the CM equations become nearly trivial. As an application an expansion for in terms of eigenfunctions of the CM equation system is obtained, where X and Y are matrices taken from one of the Gaussian ensembles, and the brackets denote an average over the angular variables.Comment: accepted by J. Phys.