Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
Articles 1 - 7 of 7
Full-Text Articles in Physics
Inverse Velocity Dependence Of Vibrationally Promoted Electron Emission From A Metal Surface, N. H. Nahler, J. D. White, Jerry L. Larue, Daniel J. Auerbach, Alec M. Wodtke
Inverse Velocity Dependence Of Vibrationally Promoted Electron Emission From A Metal Surface, N. H. Nahler, J. D. White, Jerry L. Larue, Daniel J. Auerbach, Alec M. Wodtke
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
All previous experimental and theoretical studies of molecular interactions at metal surfaces show that electronically nonadiabatic influences increase with molecular velocity. We report the observation of a nonadiabatic electronic effect that follows the opposite trend: The probability of electron emission from a low–work function surface—Au(111) capped by half a monolayer of Cs—increases as the velocity of the incident NO molecule decreases during collisions with highly vibrationally excited NO(X2π½, V = 18; V is the vibrational quantum number of NO), reaching 0.1 at the lowest velocity studied. We show that these results are consistent with a vibrational …
Discriminating Orthogonal Single-Photon Images, Curtis J. Broadbent, Petros Zerom, Heedeuk Shin, John C. Howell, Robert W. Boyd
Discriminating Orthogonal Single-Photon Images, Curtis J. Broadbent, Petros Zerom, Heedeuk Shin, John C. Howell, Robert W. Boyd
Mathematics, Physics, and Computer Science Faculty Articles and Research
We can encode an image from an orthogonal basis set onto a single photon from a downconverted pair via the use of an amplitude mask. We can then discriminate the image imprinted on the photon from other images in the set using holographic-matched filtering techniques. We demonstrate this procedure experimentally for an image space of two objects, and we discuss the possibility of applying this method to a much larger image space. This process could have important implications for the manipulation of images at the quantum level.
Preservation Of Energy-Time Entanglement In A Slow Light Medium, Curtis J. Broadbent, Ryan M. Camacho, Ran Xin, John C. Howell
Preservation Of Energy-Time Entanglement In A Slow Light Medium, Curtis J. Broadbent, Ryan M. Camacho, Ran Xin, John C. Howell
Mathematics, Physics, and Computer Science Faculty Articles and Research
We demonstrate the preservation of entanglement of an energy-time entangled biphoton through a slow light medium. Using the D1 and D2 fine structure resonances of Rubidium, we delay one photon of the 1.5 THz biphoton by ∼1.3 correlation lengths and measure the fourth order correlation fringes. After the group delay the fringe visibility is reduced from 97.0±4.4% to 80.0±4.8%, but is still sufficient to violate a Bell inequality. We show that temporal broadening is the primary mechanism for reducing the fringe visibility and that smaller bandwidths lead to greatly reduced broadening.
Storage And Retrieval Of Multimode Transverse Images In Hot Atomic Rubidium Vapor, Praveen K. Vudyasetu, Ryan M. Camacho, John C. Howell
Storage And Retrieval Of Multimode Transverse Images In Hot Atomic Rubidium Vapor, Praveen K. Vudyasetu, Ryan M. Camacho, John C. Howell
Mathematics, Physics, and Computer Science Faculty Articles and Research
We report on the experimental realization of the storage of images in a hot vapor of Rubidium atoms. The images are stored in and retrieved from the long-lived ground state atomic coherences. We show that an image impressed onto a 500 ns pulse can be stored and retrieved up to 30 μs later. The image storage is made robust to diffusion by storing the Fourier transform of the image.
Nonclassicality Without Entanglement Enables Bit Commitment, Howard Barnum, Oscar C. O. Dahlsten, Matthew S. Leifer, Ben Toner
Nonclassicality Without Entanglement Enables Bit Commitment, Howard Barnum, Oscar C. O. Dahlsten, Matthew S. Leifer, Ben Toner
Mathematics, Physics, and Computer Science Faculty Articles and Research
We investigate the existence of secure bit commitment protocols in the convex framework for probabilistic theories. The framework makes only minimal assumptions, and can be used to formalize quantum theory, classical probability theory, and a host of other possibilities. We prove that in all such theories that are locally non-classical but do not have entanglement, there exists a bit commitment protocol that is exponentially secure in the number of systems used.
Quantum Graphical Models And Belief Propagation, Matthew S. Leifer, D. Poulin
Quantum Graphical Models And Belief Propagation, Matthew S. Leifer, D. Poulin
Mathematics, Physics, and Computer Science Faculty Articles and Research
Belief Propagation algorithms acting on Graphical Models of classical probability distributions, such as Markov Networks, Factor Graphs and Bayesian Networks, are amongst the most powerful known methods for deriving probabilistic inferences amongst large numbers of random variables. This paper presents a generalization of these concepts and methods to the quantum case, based on the idea that quantum theory can be thought of as a noncommutative, operator-valued, generalization of classical probability theory. Some novel characterizations of quantum conditional independence are derived, and definitions of Quantum n-Bifactor Networks, Markov Networks, Factor Graphs and Bayesian Networks are proposed. The structure of Quantum Markov …
Color Transparency In Qcd And Post-Selection In Quantum Mechanics, Shmuel Nussinov, Jeff Tollaksen
Color Transparency In Qcd And Post-Selection In Quantum Mechanics, Shmuel Nussinov, Jeff Tollaksen
Mathematics, Physics, and Computer Science Faculty Articles and Research
We discuss color transparency in the nuclear QCD context from the perspective of pre- and post-selected ensembles. We show that the small size of the hadronic states can be explained by the peculiar "force of post-selection," in contrast to the more standard explanation based on external forces.