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- Algorithms (1)
- COHERENT STATES GCS; SPIN DYNAMICS QSD; GENERAL-RELATIVITY; AREA (1)
- Coded aperture; X-ray microscope; full-field; fluorescence (1)
- Lattice Quantum Field Theory; Gauge Symmetry; Nonperturbative Effects; Beyond Standard Model; MATRIX PRODUCT STATES; RENORMALIZATION-GROUP; GCS; BOUNDS (1)
- NOISE (1)
Articles 1 - 6 of 6
Full-Text Articles in Physics
A Coded Aperture Microscope For X-Ray Fluorescence Full-Field Imaging, D. P. Siddons, A. J. Kuczewski, A. K. Rumaiz, R. Tappero, M Idir, K. Nakhoda, J. Khanfri, V. Singh, E. R. Farquhar, M. Sullivan, D. Abel, D. J. Brady, X. Yuan
A Coded Aperture Microscope For X-Ray Fluorescence Full-Field Imaging, D. P. Siddons, A. J. Kuczewski, A. K. Rumaiz, R. Tappero, M Idir, K. Nakhoda, J. Khanfri, V. Singh, E. R. Farquhar, M. Sullivan, D. Abel, D. J. Brady, X. Yuan
Faculty Publications
The design and construction of an instrument for full-field imaging of the X-ray fluorescence emitted by a fully illuminated sample are presented. The aim is to produce an X-ray microscope with a few micrometers spatial resolution, which does not need to scan the sample. Since the fluorescence from a spatially inhomogeneous sample may contain many fluorescence lines, the optic which will provide the magnification of the emissions must be achromatic, i.e. its optical properties must be energy-independent. The only optics which fulfill this requirement in the X-ray regime are mirrors and pinholes. The throughput of a simple pinhole is very …
Demonstration Of Dynamic Thermal Compensation For Parametric Instability Suppression In Advanced Ligo, T. Hardwick, V. J. Hamedan, C. Blair, A. C. Green, D. Vander-Hyde
Demonstration Of Dynamic Thermal Compensation For Parametric Instability Suppression In Advanced Ligo, T. Hardwick, V. J. Hamedan, C. Blair, A. C. Green, D. Vander-Hyde
Faculty Publications
Advanced LIGO and other ground-based interferometric gravitational-wave detectors use high laser power to minimize shot noise and suspended optics to reduce seismic noise coupling. This can result in an opto-mechanical coupling which can become unstable and saturate the interferometer control systems. The severity of these parametric instabilities scales with circulating laser power and first hindered LIGO operations in 2014. Static thermal tuning and active electrostatic damping have previously been used to control parametric instabilities at lower powers but are insufficient as power is increased. Here we report the first demonstration of dynamic thermal compensation to avoid parametric instability in an …
Quantum Backaction Cancellation In The Audio Band, Jonathan Cripe, Torrey Cullen, Yanbei Chen, Paula Heu, David Follman, Garrett D. Cole, Thomas Corbitt
Quantum Backaction Cancellation In The Audio Band, Jonathan Cripe, Torrey Cullen, Yanbei Chen, Paula Heu, David Follman, Garrett D. Cole, Thomas Corbitt
Faculty Publications
We report on the cancellation of quantum backaction noise in an optomechanical cavity. We perform measurements of the displacement of the microresonator, one in reflection of the cavity and one in transmission of the cavity. We show that measuring the amplitude quadrature of the light transmitted by the optomechanical cavity allows us to cancel the backaction noise between 2 and 50 kHz as a consequence of the strong optical spring present in the detuned cavity. This cancellation yields a more sensitive measurement of the microresonator's position with a 2 dB increase in sensitivity. To confirm that the backaction is eliminated, …
Modifications To Gravitational Wave Equation From Canonical Quantum Gravity, Andrea Dapor, Klaus Liegener
Modifications To Gravitational Wave Equation From Canonical Quantum Gravity, Andrea Dapor, Klaus Liegener
Faculty Publications
It is expected that the quantum nature of spacetime leaves its imprint in all semiclassical gravitational systems, at least in certain regimes, including gravitational waves. In this paper we investigate such imprints on gravitational waves within a specific framework: space is assumed to be discrete (in the form of a regular cubic lattice), and this discrete geometry is quantised following Dirac's canonical quantisation scheme. The semiclassical behavior is then extracted by promoting the expectation value of the Hamiltonian operator on a semiclassical state to an effective Hamiltonian. Considering a family of semiclassical states representing small tensor perturbations to Minkowski background, …
Noise Resilience Of Variational Quantum Compiling, Kunal Sharma, Sumeet Khatri2, M. Cerezo, Patrick J. Coles
Noise Resilience Of Variational Quantum Compiling, Kunal Sharma, Sumeet Khatri2, M. Cerezo, Patrick J. Coles
Faculty Publications
Variational hybrid quantum-classical algorithms (VHQCAs) are near-term algorithms that leverage classical optimization to minimize a cost function, which is efficiently evaluated on a quantum computer. Recently VHQCAs have been proposed for quantum compiling, where a target unitary U is compiled into a short-depth gate sequence V. In this work, we report on a surprising form of noise resilience for these algorithms. Namely, we find one often learns the correct gate sequence V (i.e. the correct variational parameters) despite various sources of incoherent noise acting during the cost-evaluation circuit. Our main results are rigorous theorems stating that the optimal variational parameters …
Expectation Values Of Coherent States For Su(2) Lattice Gauge Theories, Klaus Liegener, Ernst-Albrecht Zwicknagel
Expectation Values Of Coherent States For Su(2) Lattice Gauge Theories, Klaus Liegener, Ernst-Albrecht Zwicknagel
Faculty Publications
This article investigates properties of semiclassical Gauge Field Theory Coherent States for general quantum gauge theories. Useful, e.g., for the canonical formulation of Lattice Gauge Theories these states are labelled by a point in the classical phase space and constructed such that the expectation values of the canonical operators are sharply peaked on said phase space point. For the case of the non-abelian gauge group SU(2), we will explicitly compute the expectation value of general polynomials including the first order quantum corrections. This allows asking more precise questions about the quantum fluctuations of any given semiclassical system.