Spin-Dependent Two-Color Kapitza-Dirac Effects,
2015
University of Nebraska-Lincoln
Spin-Dependent Two-Color Kapitza-Dirac Effects, Scot Mcgregor, Wayne Cheng-Wei Huang, Herman Batelaan, Bradley Allan Shadwick
Department of Physics and Astronomy: Faculty Publications
In this paper we present an analysis of the spin behavior of electrons propagating through a laser field. We present an experimentally realizable scenario in which spin-dependent effects of the interaction between the laser and the electrons are dominant. The laser interaction strength and incident electron velocity are in the nonrelativistic domain. This analysis may thus lead to novel methods of creating and characterizing spin-polarized nonrelativistic femtosecond electron pulses.
Experimental Design And Construction For Critical Velocity Measurement In Spin-Orbit Coupled Bose-Einstein Condensates,
2015
Purdue University
Experimental Design And Construction For Critical Velocity Measurement In Spin-Orbit Coupled Bose-Einstein Condensates, Ting-Wei Hsu, Yong P. Chen
The Summer Undergraduate Research Fellowship (SURF) Symposium
Quantum simulation using ultra-cold atoms, such as Bose-Einstein Condensates (BECs), offers a very flexible and well controlled environment to simulate physics in different systems. For example, to simulate the effects of spin orbit coupling (SOC) on electrons in solid state systems, we can make a SOC BEC which mimics the behavior of SOC electrons. The goal of this project is to see how the superfluid property of BECs change in the presence of SOC. In particular, we plan to measure the critical velocity of an 87Rb BEC with and without SOC by stirring it with a laser. This laser needs …
Device-Independent Relativistic Quantum Bit Commitment,
2015
Chapman University
Device-Independent Relativistic Quantum Bit Commitment, Emily Adlam, Adrian Kent
Mathematics, Physics, and Computer Science Faculty Articles and Research
We examine the possibility of device-independent relativistic quantum bit commitment, introducing three relativistic quantum bit commitment schemes that offer device-independent security against hypothetical postquantum adversaries subject only to the no-signaling principle. We discuss the potential threat of location attacks, in which the behavior of untrusted devices used in relativistic quantum cryptography depends on their space-time location and show that our protocols are secure against both location attacks and memory attacks. The protocols are compared to a relativistic classical bit commitment scheme with similar features and we note some advantages for the quantum schemes.
Infographics And Mathematics: A Mechanism For Effective Learning In The Classroom,
2015
University of Dayton
Infographics And Mathematics: A Mechanism For Effective Learning In The Classroom, Ivan Sudakov, Thomas Bellsky, Svetlana Usenyuk, Victoria V. Polyakova
Physics Faculty Publications
This work discusses the creation and use of infographies in an undergraduate mathematics course. Infographies are a visualization of information combining data, formulas, and images. This article discusses how to form an infographic and uses infographics on topics within mathematics and climate as examples. It concludes with survey data from undergraduate students on both the general use of infographics and on the specific infographics designed by the authors.
Comment On "Role Of Potentials In The Aharonov-Bohm Effect",
2015
Chapman University
Comment On "Role Of Potentials In The Aharonov-Bohm Effect", Yakir Aharonov, Eliahu Cohen, Daniel Rohrlich
Mathematics, Physics, and Computer Science Faculty Articles and Research
Are the electromagnetic scalar and vector potentials dispensable? Vaidman [Phys. Rev. A 86, 040101(R) (2012)] has suggested that local interactions of gauge-invariant quantities, e.g., magnetic torques, suffice for the description of all quantum electromagnetic phenomena. We analyze six thought experiments that challenge this suggestion. All of them have explanations in terms of local interactions of gauge-dependent quantities, and, in addition, some have explanations in terms of nonlocal interactions of gauge-invariant quantities. We claim, however, that two of our examples have no gauge-invariant formal description and that, in general, no local description can dispense with electromagnetic potentials.
Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction,
2015
Ursinus College
Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction, Jacob T. Paul, Matan Peleg
Physics and Astronomy Summer Fellows
In our project we ran computations on a supercomputer to simulate experiments performed on highly excited atoms at μK temperatures. At μK temperatures the atoms are moving slowly so there are essentially no collisions of the atoms on the time scales at which we perform our experiments. In the absence of collisions the atoms exchange energy through long range dipole-dipole interactions. This exchange depends on the distances between and relative orientation of the atoms. The angular dependence between two atoms has recently been studied experimentally1 . We simulate experimentally accessible spatial arrangements to see if the effect of the …
Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction,
2015
Ursinus College
Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction, Matan Peleg, Jacob T. Paul
Physics and Astronomy Summer Fellows
We conducted simulations of Rydberg atoms in a magneto-optical trap using the supercomputer available on campus and the COMET supercomputer provided by the NSF. Our research focused on the angular dependence of the long range interaction between Rydberg atoms. We simulated randomly distributed atoms alligned with a magnetic and electric field. We compared the simulated interaction rates for different electric field directions.
Toward Quantum Analog Computing: Simulating Designer Atomic Systems,
2015
Ursinus College
Toward Quantum Analog Computing: Simulating Designer Atomic Systems, Veronica L. Sanford, Jacob L. Bigelow
Physics and Astronomy Summer Fellows
We use a magneto-optical trap to cool rubidium atoms to temperatures in the µK range. On the µs timescales of our experiment, the atoms are moving slowly enough that they appear stationary. We then excite them to a Rydberg state, where the outer electron is loosely bound. In these high energy states, the atoms can exchange energy with each other. Since the energy exchange depends on the separation and the relative orientation of the atoms, we can potentially control their interactions by controlling the spatial arrangements of the atoms. We model this system using simulations on a supercomputer …
Toward Analog Quantum Computing: Simulating Designer Atomic Systems,
2015
Ursinus College
Toward Analog Quantum Computing: Simulating Designer Atomic Systems, Jacob L. Bigelow, Veronica L. Sanford
Physics and Astronomy Summer Fellows
We use a magneto-optical trap to cool rubidium atoms to temperatures in the µK range. On the µs timescales of our experiment, the atoms are moving slowly enough that they appear stationary. We then excite them to a Rydberg state, where the outer electron is loosely bound. In these high energy states, the atoms can exchange energy with each other. Since the energy exchange depends on the separation and the relative orientation of the atoms, we can potentially control their interactions by controlling the spatial arrangements of the atoms. We model this system using simulations on a supercomputer …
Application Of Resurgence Theory To Approximate Inverse Square Potential In Quantum Mechanics,
2015
Macalester College
Application Of Resurgence Theory To Approximate Inverse Square Potential In Quantum Mechanics, Jian Zhang Ms.
Macalester Journal of Physics and Astronomy
Previous work concluded that the leading term of the energy spectrum of a quantum particle moving in an inverse-square law potential with regulated singularity is non-perturvative in nature. Trans-series and resurgence theory predicts the emergence of perturbative, and potentially logarithmic, corrections to the leading behavior. This talk relates an attempt to systematically calculate such corrections for the first time.
Static And Dynamical Properties Of Ferroelectrics And Related Material In Bulk And Nanostructure Forms,
2015
University of Arkansas, Fayetteville
Static And Dynamical Properties Of Ferroelectrics And Related Material In Bulk And Nanostructure Forms, Zhigang Gui
Graduate Theses and Dissertations
Ferroelectrics (FE) and multiferroics (MFE) have attracted a lot of attentions due to their rich and novel properties. Studies towards FE and MFE are of both fundamental and technological importance. We use a first-principles-based effective Hamiltonian method, conventional ab-initio packages and linear-scale three-dimension fragment method to investigate several important issues about FE and MFE. Tuning the properties of FE and MFE films are essential for miniaturized device applications, which can be realized through epitaxial strain and growth direction. In this dissertation, we use the effective Hamiltonian method to study (i) BaTiO 3 films grown along the (110) pseudocubic direction on …
Shifting The Quantum-Classical Boundary: Theory And Experiment For Statistically Classical Optical Fields,
2015
University of Rochester
Shifting The Quantum-Classical Boundary: Theory And Experiment For Statistically Classical Optical Fields, Xiao-Feng Qian, Bethany Little, John C. Howell, Joseph H. Eberly
Mathematics, Physics, and Computer Science Faculty Articles and Research
The growing recognition that entanglement is not exclusively a quantum property, and does not even originate with Schrödinger’s famous remark about it [Proc. Cambridge Philos. Soc. 31, 555 (1935)], prompts the examination of its role in marking the quantum-classical boundary. We have done this by subjecting correlations of classical optical fields to new Bell-analysis experiments and report here values of the Bell parameter greater than ℬ=2.54. This is many standard deviations outside the limit ℬ=2 established by the Clauser–Horne–Shimony–Holt Bell inequality [Phys. Rev. Lett. 23, 880 (1969)], in agreement with our theoretical classical prediction, and not far from the Tsirelson …
How To Measure Magnetic Flux With A Single Position Measurement?,
2015
Tel Aviv University
How To Measure Magnetic Flux With A Single Position Measurement?, Eliahu Cohen, Lev Vaidman, Yakir Aharonov
Mathematics, Physics, and Computer Science Faculty Articles and Research
Current methods for measuring magnetic flux are based on performing many measurements over a large ensemble of electrons. We propose a novel method based on wave function "revival" for measuring the flux modulo using only a single electron. A preliminary analysis of the feasibility of the experiment is provided.
Spacetime Algebra As A Powerful Tool For Electromagnetism,
2015
Chapman University
Spacetime Algebra As A Powerful Tool For Electromagnetism, Justin Dressel, Konstantin Y. Bliokh, Franco Nori
Mathematics, Physics, and Computer Science Faculty Articles and Research
We present a comprehensive introduction to spacetime algebra that emphasizes its practicality and power as a tool for the study of electromagnetism. We carefully develop this natural (Clifford) algebra of the Minkowski spacetime geometry, with a particular focus on its intrinsic (and often overlooked) complex structure. Notably, the scalar imaginary that appears throughout the electromagnetic theory properly corresponds to the unit 4-volume of spacetime itself, and thus has physical meaning. The electric and magnetic fields are combined into a single complex and frame-independent bivector field, which generalizes the Riemann-Silberstein complex vector that has recently resurfaced in studies of the single …
Transition Orbits Of Walking Droplets,
2015
California Polytechnic State University - San Luis Obispo
Transition Orbits Of Walking Droplets, Joshua Parker
Physics
It was recently discovered that millimeter-sized droplets bouncing on the surface of an oscillating bath of the same fluid can couple with the surface waves it produces and begin walking across the fluid bath. These walkers have been shown to behave similarly to quantum particles; a few examples include single-particle diffraction, tunneling, and quantized orbits. Such behavior occurs because the drop and surface waves depend on each other to exist, making this the first and only known macroscopic pilot-wave system. In this paper, the quantized orbits between two identical drops are explored. By sending a perturbation to a pair of …
Mirror Buckling Transitions In Freestanding Graphene Membranes Induced Through Scanning Tunneling Microscopy,
2015
University of Arkansas, Fayetteville
Mirror Buckling Transitions In Freestanding Graphene Membranes Induced Through Scanning Tunneling Microscopy, James Kevin Schoelz
Graduate Theses and Dissertations
Graphene has the ability to provide for a technological revolution. First isolated and characterized in 2004, this material shows promise in the field of flexible electronics. The electronic properties of graphene can be tuned by controlling the shape of the membrane. Of particular interest in this endeavor are the thermal ripples in graphene membranes. Years of theoretical work by such luminaries as Lev Landau, Rudolf Peierls, David Mermin and Herbert Wagner have established that 2D crystals should not be thermodynamically stable. Experimental research on thin films has supported this finding. Yet graphene exists, and freestanding graphene films have been grown …
Structure Of Local Quantum Operations And Classical Communication: Finite Versus Infinite Rounds,
2015
Portland State University
Structure Of Local Quantum Operations And Classical Communication: Finite Versus Infinite Rounds, Scott M. Cohen
Physics Faculty Publications and Presentations
Every measurement that can be implemented by local quantum operations and classical communication (LOCC) using an infinite number of rounds is the limit of a sequence of measurements, where each measurement in the sequence requires only a finite number of rounds. This rather obvious and well-known fact is nonetheless of interest as it shows that these infinite-round measurements can be approximated arbitrarily closely simply by using more and more rounds of communication. Here we demonstrate the perhaps less obvious result that (at least) for bipartite systems, the reverse relationship also holds. Specifically, we show that every finite-round bipartite LOCC measurement …
Violating The Modified Helstrom Bound With Nonprojective Measurements,
2015
Chapman University
Violating The Modified Helstrom Bound With Nonprojective Measurements, Justin Dressel, Todd A. Brun, Alexander N. Korotkov
Mathematics, Physics, and Computer Science Faculty Articles and Research
We consider the discrimination of two pure quantum states with three allowed outcomes: a correct guess, an incorrect guess, and a nonguess. To find an optimum measurement procedure, we define a tunable cost that penalizes the incorrect guess and nonguess outcomes. Minimizing this cost over all projective measurements produces a rigorous cost bound that includes the usual Helstrom discrimination bound as a special case.We then show that nonprojective measurements can outperform this modified Helstrom bound for certain choices of cost function. The Ivanovic-Dieks-Peres unambiguous state discrimination protocol is recovered as a special case of this improvement.Notably, while the cost advantage …
Modular Approach To Spintronics,
2015
Purdue University
Modular Approach To Spintronics, Kerem Yunus Camsari
Open Access Dissertations
There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building blocks that could be exploited in designing transistor-like functional devices of the future. The objective of this thesis is to provide a quantitative foundation for this building block approach, so that new discoveries can be integrated into functional device concepts, quickly analyzed and critically evaluated. Through careful benchmarking against available theory and experiments we establish …
Can A Future Choice Affect A Past Measurement's Outcome?,
2015
Chapman University
Can A Future Choice Affect A Past Measurement's Outcome?, Yakir Aharonov, Eliahu Cohen, Avshalom C. Elitzur
Mathematics, Physics, and Computer Science Faculty Articles and Research
An EPR experiment is studied where each particle within the entangled pair undergoes a few weak measurements (WMs) along some pre-set spin orientations, with the outcomes individually recorded. Then the particle undergoes one strong measurement along an orientation chosen at the last moment. Bell-inequality violation is expected between the two final measurements within each EPR pair. At the same time, statistical agreement is expected between these strong measurements and the earlier weak ones performed on that pair. A contradiction seemingly ensues: (i) Bell’s theorem forbids spin values to exist prior to the choice of the orientation measured; (ii) A weak …
