Search

Your search keyword '"Neill C"' showing total 39 results
Start Over Author "Neill C" Publisher american physical society (aps)
39 results on '"Neill C"'

2. Complex paths around the sign problem

Author

Alexandru, Andrei, Basar, Gokce, Bedaque, Paulo F., and Warrington, Neill C.

Subjects
Nuclear Theory (nucl-th), High Energy Physics - Theory, Condensed Matter - Strongly Correlated Electrons, Quantum Physics, High Energy Physics - Lattice, Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th), Nuclear Theory, High Energy Physics - Lattice (hep-lat), FOS: Physical sciences, General Physics and Astronomy, Quantum Physics (quant-ph)
Abstract

The Monte Carlo evaluation of path integrals is one of a few general purpose methods to approach strongly coupled systems. It is used in all branches of Physics, from QCD/nuclear physics to the correlated electron systems. However, many systems of great importance (dense matter inside neutron stars, the repulsive Hubbard model away from half-filling, dynamical and non-equilibrium observables) are not amenable to the Monte Carlo method as it currently stands due to the so-called "sign-problem". We review a new set of ideas recently developed to tackle the sign problem based on the complexification of field space and the Picard-Lefshetz theory accompanying it. The mathematical ideas underpinning this approach, as well as the algorithms so far developed, are described together with non-trivial examples where the method has already been proved successful. Directions of future work, including the burgeoning use of machine learning techniques, are delineated., 35 pages, 21 figures

Published
2022
Full Text
View/download PDF

3. Path integral contour deformations for noisy observables

Author

Massachusetts Institute of Technology. Center for Theoretical Physics, Massachusetts Institute of Technology. Department of Physics, Detmold, William, Kanwar, Gurtej S., Wagman, Michael L, Warrington, Neill C., Massachusetts Institute of Technology. Center for Theoretical Physics, Massachusetts Institute of Technology. Department of Physics, Detmold, William, Kanwar, Gurtej S., Wagman, Michael L, and Warrington, Neill C.

Published
2022

4. Path integral contour deformations for observables in SU(N) gauge theory

Author

Massachusetts Institute of Technology. Center for Theoretical Physics, Massachusetts Institute of Technology. Department of Physics, Detmold, William, Kanwar, Gurtej, Lamm, Henry, Wagman, Michael L, Warrington, Neill C, Massachusetts Institute of Technology. Center for Theoretical Physics, Massachusetts Institute of Technology. Department of Physics, Detmold, William, Kanwar, Gurtej, Lamm, Henry, Wagman, Michael L, and Warrington, Neill C

Published
2022

5. Direct measurement of nonlocal interactions in the many-body localized phase

Author

Chiaro, B., primary, Neill, C., additional, Bohrdt, A., additional, Filippone, M., additional, Arute, F., additional, Arya, K., additional, Babbush, R., additional, Bacon, D., additional, Bardin, J., additional, Barends, R., additional, Boixo, S., additional, Buell, D., additional, Burkett, B., additional, Chen, Y., additional, Chen, Z., additional, Collins, R., additional, Dunsworth, A., additional, Farhi, E., additional, Fowler, A., additional, Foxen, B., additional, Gidney, C., additional, Giustina, M., additional, Harrigan, M., additional, Huang, T., additional, Isakov, S., additional, Jeffrey, E., additional, Jiang, Z., additional, Kafri, D., additional, Kechedzhi, K., additional, Kelly, J., additional, Klimov, P., additional, Korotkov, A., additional, Kostritsa, F., additional, Landhuis, D., additional, Lucero, E., additional, McClean, J., additional, Mi, X., additional, Megrant, A., additional, Mohseni, M., additional, Mutus, J., additional, McEwen, M., additional, Naaman, O., additional, Neeley, M., additional, Niu, M., additional, Petukhov, A., additional, Quintana, C., additional, Rubin, N., additional, Sank, D., additional, Satzinger, K., additional, White, T., additional, Yao, Z., additional, Yeh, P., additional, Zalcman, A., additional, Smelyanskiy, V., additional, Neven, H., additional, Gopalakrishnan, S., additional, Abanin, D., additional, Knap, M., additional, Martinis, J., additional, and Roushan, P., additional

Published
2022
Full Text
View/download PDF

6. Path integral contour deformations for observables in SU(N) gauge theory

Author

Neill C. Warrington, Gurtej Kanwar, Michael L. Wagman, William Detmold, and Henry Lamm

Subjects
Physics, Field (physics), 010308 nuclear & particles physics, High Energy Physics::Lattice, Observable, Expectation value, 01 natural sciences, Lattice (module), Lattice gauge theory, 0103 physical sciences, Path integral formulation, Gauge theory, 010306 general physics, Sign (mathematics), Mathematical physics
Abstract

Path integral contour deformations have been shown to mitigate sign and signal-to-noise problems associated with phase fluctuations in lattice field theories. We define a family of contour deformations applicable to $SU(N)$ lattice gauge theory that can reduce sign and signal-to-noise problems associated with complex actions and complex observables. For observables, these contours can be used to define deformed observables with identical expectation value but different variance. As a proof-of-principle, we apply machine learning techniques to optimize the deformed observables associated with Wilson loops in two dimensional $SU(2)$ and $SU(3)$ gauge theory. We study loops consisting of up to 64 plaquettes and achieve variance reduction of up to 4 orders of magnitude.

Published
2021
Full Text
View/download PDF

13. Fermions at Finite Density in 2+1 Dimensions with Sign-Optimized Manifolds

Author

Scott Lawrence, Neill C. Warrington, Henry Lamm, Paulo F. Bedaque, and Andrei Alexandru

Subjects
Physics, Thirring model, 010308 nuclear & particles physics, Monte Carlo method, General Physics and Astronomy, Fermion, 01 natural sciences, Complex space, Lattice (order), 0103 physical sciences, Path integral formulation, Parametric family, 010306 general physics, Mathematical physics
Abstract

We present Monte Carlo calculations of the thermodynamics of the (2+1)-dimensional Thirring model at finite density. We bypass the sign problem by deforming the domain of integration of the path integral into complex space in such a way as to maximize the average sign within a parameterized family of manifolds. We present results for lattice sizes up to 103 and we find that at high densities and/or temperatures the chiral condensate is abruptly reduced.

Published
2018
Full Text
View/download PDF

14. Diabatic Gates for Frequency-Tunable Superconducting Qubits

Author

Barends, R., primary, Quintana, C. M., additional, Petukhov, A. G., additional, Chen, Yu, additional, Kafri, D., additional, Kechedzhi, K., additional, Collins, R., additional, Naaman, O., additional, Boixo, S., additional, Arute, F., additional, Arya, K., additional, Buell, D., additional, Burkett, B., additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Foxen, B., additional, Fowler, A., additional, Gidney, C., additional, Giustina, M., additional, Graff, R., additional, Huang, T., additional, Jeffrey, E., additional, Kelly, J., additional, Klimov, P. V., additional, Kostritsa, F., additional, Landhuis, D., additional, Lucero, E., additional, McEwen, M., additional, Megrant, A., additional, Mi, X., additional, Mutus, J., additional, Neeley, M., additional, Neill, C., additional, Ostby, E., additional, Roushan, P., additional, Sank, D., additional, Satzinger, K. J., additional, Vainsencher, A., additional, White, T., additional, Yao, J., additional, Yeh, P., additional, Zalcman, A., additional, Neven, H., additional, Smelyanskiy, V. N., additional, and Martinis, John M., additional

Published
2019
Full Text
View/download PDF

15. Tempered transitions between thimbles

Author

Andrei Alexandru, Neill C. Warrington, Gökçe Başar, and Paulo F. Bedaque

Subjects
Physics, Thirring model, 010308 nuclear & particles physics, High Energy Physics - Lattice (hep-lat), Monte Carlo method, Holomorphic function, FOS: Physical sciences, Sampling (statistics), 01 natural sciences, High Energy Physics - Lattice, Quantum mechanics, 0103 physical sciences, Applied mathematics, Probability distribution, Quantum field theory, 010306 general physics, Importance sampling, Sign (mathematics)
Abstract

Quantum field theories with complex actions cannot be investigated using importance sampling due to the sign problem. One possible solution is to use the holomorphic gradient flow, a method we introduced related to the Lefschetz thimbles idea. In many cases the probability distribution generated by this method is multi-modal and standard Monte-Carlo sampling fails. We propose an algorithm that incorporates tempered proposals to solve this problem. We apply this algorithm to the 0+1 dimensional Thirring model at finite density for a parameter set where standard sampling fails and show that tempered proposals cure this problem., 10 pages, 6 figures

Published
2017
Full Text
View/download PDF

18. Fluctuations of Energy-Relaxation Times in Superconducting Qubits

Author

Klimov, P. V., primary, Kelly, J., additional, Chen, Z., additional, Neeley, M., additional, Megrant, A., additional, Burkett, B., additional, Barends, R., additional, Arya, K., additional, Chiaro, B., additional, Chen, Yu, additional, Dunsworth, A., additional, Fowler, A., additional, Foxen, B., additional, Gidney, C., additional, Giustina, M., additional, Graff, R., additional, Huang, T., additional, Jeffrey, E., additional, Lucero, Erik, additional, Mutus, J. Y., additional, Naaman, O., additional, Neill, C., additional, Quintana, C., additional, Roushan, P., additional, Sank, Daniel, additional, Vainsencher, A., additional, Wenner, J., additional, White, T. C., additional, Boixo, S., additional, Babbush, R., additional, Smelyanskiy, V. N., additional, Neven, H., additional, and Martinis, John M., additional

Published
2018
Full Text
View/download PDF

20. Fast estimator of Jacobians in the Monte Carlo integration on Lefschetz thimbles

Author

Neill C. Warrington, Andrei Alexandru, Gregory W. Ridgway, Gökçe Başar, and Paulo F. Bedaque

Subjects
Physics, 010308 nuclear & particles physics, High Energy Physics - Lattice (hep-lat), Mathematical analysis, FOS: Physical sciences, Order (ring theory), Submanifold, 01 natural sciences, symbols.namesake, High Energy Physics - Lattice, Complex space, Quantum mechanics, 0103 physical sciences, Jacobian matrix and determinant, symbols, Monte Carlo integration, 010306 general physics, Complex plane, Parametrization, Sign (mathematics)
Abstract

A solution to the sign problem is the so-called "Lefschetz thimble approach" where the domain of integration for field variables in the path integral is deformed from the real axis to a sub-manifold in the complex space. For properly chosen sub-manifolds ("thimbles") the sign problem disappears or is drastically alleviated. The parametrization of the thimble by real coordinates require the calculation of a jacobian with a computational cost of order O(V^3), where V is proportional to the spacetime volume. In this note we propose two estimators for this jacobian with a computational cost of order O(V). We discuss analytically the regimes where we expect the estimator to work and show numerical examples in two different models., 10 pages, 3 figures

Published
2016
Full Text
View/download PDF

22. Observation of Classical-Quantum Crossover of 1/f Flux Noise and Its Paramagnetic Temperature Dependence

Author

Quintana, C. M., primary, Chen, Yu, additional, Sank, D., additional, Petukhov, A. G., additional, White, T. C., additional, Kafri, Dvir, additional, Chiaro, B., additional, Megrant, A., additional, Barends, R., additional, Campbell, B., additional, Chen, Z., additional, Dunsworth, A., additional, Fowler, A. G., additional, Graff, R., additional, Jeffrey, E., additional, Kelly, J., additional, Lucero, E., additional, Mutus, J. Y., additional, Neeley, M., additional, Neill, C., additional, O’Malley, P. J. J., additional, Roushan, P., additional, Shabani, A., additional, Smelyanskiy, V. N., additional, Vainsencher, A., additional, Wenner, J., additional, Neven, H., additional, and Martinis, John M., additional

Published
2017
Full Text
View/download PDF

24. Measurement-Induced State Transitions in a Superconducting Qubit: Beyond the Rotating Wave Approximation

Author

Sank, Daniel, primary, Chen, Zijun, additional, Khezri, Mostafa, additional, Kelly, J., additional, Barends, R., additional, Campbell, B., additional, Chen, Y., additional, Chiaro, B., additional, Dunsworth, A., additional, Fowler, A., additional, Jeffrey, E., additional, Lucero, E., additional, Megrant, A., additional, Mutus, J., additional, Neeley, M., additional, Neill, C., additional, O’Malley, P. J. J., additional, Quintana, C., additional, Roushan, P., additional, Vainsencher, A., additional, White, T., additional, Wenner, J., additional, Korotkov, Alexander N., additional, and Martinis, John M., additional

Published
2016
Full Text
View/download PDF

25. Scalablein situqubit calibration during repetitive error detection

Author

Kelly, J., primary, Barends, R., additional, Fowler, A. G., additional, Megrant, A., additional, Jeffrey, E., additional, White, T. C., additional, Sank, D., additional, Mutus, J. Y., additional, Campbell, B., additional, Chen, Yu, additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Lucero, E., additional, Neeley, M., additional, Neill, C., additional, O'Malley, P. J. J., additional, Quintana, C., additional, Roushan, P., additional, Vainsencher, A., additional, Wenner, J., additional, and Martinis, John M., additional

Published
2016
Full Text
View/download PDF

28. Scalable Quantum Simulation of Molecular Energies

Author

O’Malley, P. J. J., primary, Babbush, R., additional, Kivlichan, I. D., additional, Romero, J., additional, McClean, J. R., additional, Barends, R., additional, Kelly, J., additional, Roushan, P., additional, Tranter, A., additional, Ding, N., additional, Campbell, B., additional, Chen, Y., additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Fowler, A. G., additional, Jeffrey, E., additional, Lucero, E., additional, Megrant, A., additional, Mutus, J. Y., additional, Neeley, M., additional, Neill, C., additional, Quintana, C., additional, Sank, D., additional, Vainsencher, A., additional, Wenner, J., additional, White, T. C., additional, Coveney, P. V., additional, Love, P. J., additional, Neven, H., additional, Aspuru-Guzik, A., additional, and Martinis, J. M., additional

Published
2016
Full Text
View/download PDF

30. Measuring and Suppressing Quantum State Leakage in a Superconducting Qubit

Author

Chen, Zijun, primary, Kelly, Julian, additional, Quintana, Chris, additional, Barends, R., additional, Campbell, B., additional, Chen, Yu, additional, Chiaro, B., additional, Dunsworth, A., additional, Fowler, A. G., additional, Lucero, E., additional, Jeffrey, E., additional, Megrant, A., additional, Mutus, J., additional, Neeley, M., additional, Neill, C., additional, O’Malley, P. J. J., additional, Roushan, P., additional, Sank, D., additional, Vainsencher, A., additional, Wenner, J., additional, White, T. C., additional, Korotkov, A. N., additional, and Martinis, John M., additional

Published
2016
Full Text
View/download PDF

31. Qubit Metrology of Ultralow Phase Noise Using Randomized Benchmarking

Author

O’Malley, P. J. J., primary, Kelly, J., additional, Barends, R., additional, Campbell, B., additional, Chen, Y., additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Fowler, A. G., additional, Hoi, I.-C., additional, Jeffrey, E., additional, Megrant, A., additional, Mutus, J., additional, Neill, C., additional, Quintana, C., additional, Roushan, P., additional, Sank, D., additional, Vainsencher, A., additional, Wenner, J., additional, White, T. C., additional, Korotkov, A. N., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2015
Full Text
View/download PDF

32. Qubit Architecture with High Coherence and Fast Tunable Coupling

Author

Chen, Yu, primary, Neill, C., additional, Roushan, P., additional, Leung, N., additional, Fang, M., additional, Barends, R., additional, Kelly, J., additional, Campbell, B., additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Jeffrey, E., additional, Megrant, A., additional, Mutus, J. Y., additional, O’Malley, P. J. J., additional, Quintana, C. M., additional, Sank, D., additional, Vainsencher, A., additional, Wenner, J., additional, White, T. C., additional, Geller, Michael R., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2014
Full Text
View/download PDF

33. Rolling quantum dice with a superconducting qubit

Author

Barends, R., primary, Kelly, J., additional, Veitia, A., additional, Megrant, A., additional, Fowler, A. G., additional, Campbell, B., additional, Chen, Y., additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Hoi, I.-C., additional, Jeffrey, E., additional, Neill, C., additional, O'Malley, P. J. J., additional, Mutus, J., additional, Quintana, C., additional, Roushan, P., additional, Sank, D., additional, Wenner, J., additional, White, T. C., additional, Korotkov, A. N., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2014
Full Text
View/download PDF

34. Optimal Quantum Control Using Randomized Benchmarking

Author

Kelly, J., primary, Barends, R., additional, Campbell, B., additional, Chen, Y., additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Fowler, A. G., additional, Hoi, I.-C., additional, Jeffrey, E., additional, Megrant, A., additional, Mutus, J., additional, Neill, C., additional, O’Malley, P. J. J., additional, Quintana, C., additional, Roushan, P., additional, Sank, D., additional, Vainsencher, A., additional, Wenner, J., additional, White, T. C., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2014
Full Text
View/download PDF

35. Catching Time-Reversed Microwave Coherent State Photons with 99.4% Absorption Efficiency

Author

Wenner, J., primary, Yin, Yi, additional, Chen, Yu, additional, Barends, R., additional, Chiaro, B., additional, Jeffrey, E., additional, Kelly, J., additional, Megrant, A., additional, Mutus, J. Y., additional, Neill, C., additional, O’Malley, P. J. J., additional, Roushan, P., additional, Sank, D., additional, Vainsencher, A., additional, White, T. C., additional, Korotkov, Alexander N., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2014
Full Text
View/download PDF

36. Fast Accurate State Measurement with Superconducting Qubits

Author

Jeffrey, Evan, primary, Sank, Daniel, additional, Mutus, J. Y., additional, White, T. C., additional, Kelly, J., additional, Barends, R., additional, Chen, Y., additional, Chen, Z., additional, Chiaro, B., additional, Dunsworth, A., additional, Megrant, A., additional, O’Malley, P. J. J., additional, Neill, C., additional, Roushan, P., additional, Vainsencher, A., additional, Wenner, J., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2014
Full Text
View/download PDF

37. Coherent Josephson Qubit Suitable for Scalable Quantum Integrated Circuits

Author

Barends, R., primary, Kelly, J., additional, Megrant, A., additional, Sank, D., additional, Jeffrey, E., additional, Chen, Y., additional, Yin, Y., additional, Chiaro, B., additional, Mutus, J., additional, Neill, C., additional, O’Malley, P., additional, Roushan, P., additional, Wenner, J., additional, White, T. C., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2013
Full Text
View/download PDF

38. Excitation of Superconducting Qubits from Hot Nonequilibrium Quasiparticles

Author

Wenner, J., primary, Yin, Yi, additional, Lucero, Erik, additional, Barends, R., additional, Chen, Yu, additional, Chiaro, B., additional, Kelly, J., additional, Lenander, M., additional, Mariantoni, Matteo, additional, Megrant, A., additional, Neill, C., additional, O’Malley, P. J. J., additional, Sank, D., additional, Vainsencher, A., additional, Wang, H., additional, White, T. C., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2013
Full Text
View/download PDF

39. Catch and Release of Microwave Photon States

Author

Yin, Yi, primary, Chen, Yu, additional, Sank, Daniel, additional, O’Malley, P. J. J., additional, White, T. C., additional, Barends, R., additional, Kelly, J., additional, Lucero, Erik, additional, Mariantoni, Matteo, additional, Megrant, A., additional, Neill, C., additional, Vainsencher, A., additional, Wenner, J., additional, Korotkov, Alexander N., additional, Cleland, A. N., additional, and Martinis, John M., additional

Published
2013
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results