Topological Insulators

... a highly desirable goal in quantum information science. Unfortunately, the only physical system in which anything approaching topological protection has been seen is a two-dimensional particle gas experiencing the fractional quantum Hall effect. That effect requires formidable extremes of low temper ...

... a highly desirable goal in quantum information science. Unfortunately, the only physical system in which anything approaching topological protection has been seen is a two-dimensional particle gas experiencing the fractional quantum Hall effect. That effect requires formidable extremes of low temper ...

PhD position: Quantum information processing with single electron spins

... PhD position: Quantum information processing with single electron spins in levitated diamonds A computer based on quantum information would be able to solve certain problems which are intractable with other types of computer. It is natural to use the spin of an electron as a quantum bit because spin ...

... PhD position: Quantum information processing with single electron spins in levitated diamonds A computer based on quantum information would be able to solve certain problems which are intractable with other types of computer. It is natural to use the spin of an electron as a quantum bit because spin ...

Thesis Presentation Mr. Joshuah T. Heath Department of Physics

... One of the simplest conceptual models in quantum statistical physics is a gas of noninteracting particles with bosonic symmetry. In the grand canonical ensemble, particle number and temperature are in equilibrium with an external reservoir and an exact analytical expression can be derived for the pa ...

... One of the simplest conceptual models in quantum statistical physics is a gas of noninteracting particles with bosonic symmetry. In the grand canonical ensemble, particle number and temperature are in equilibrium with an external reservoir and an exact analytical expression can be derived for the pa ...

How does a Bohm particle localize?

... arises without internal contradictions as the Bohm trajectories are not allowed to cross each other. The comparison of the trajectories to the semi-classical characteristics such as scar states, etc., should also be most interesting, particularly their variation with magnetic flux. In a fully locali ...

... arises without internal contradictions as the Bohm trajectories are not allowed to cross each other. The comparison of the trajectories to the semi-classical characteristics such as scar states, etc., should also be most interesting, particularly their variation with magnetic flux. In a fully locali ...

Mott insulators, Noise correlations and Coherent Spin Dynamics in Optical Lattices

... Similar to Richard Feynman’s original proposal for a quantum computer as a simulator for the quantum dynamics of other physical systems, neutral atoms in optical lattices already today offer powerful possibilities for simulating fundamental Hamiltonians of condensed matter physics. In fact, many nov ...

... Similar to Richard Feynman’s original proposal for a quantum computer as a simulator for the quantum dynamics of other physical systems, neutral atoms in optical lattices already today offer powerful possibilities for simulating fundamental Hamiltonians of condensed matter physics. In fact, many nov ...

4.2 The Quantum Model of the Atom Vocab Electromagnetic

... - A unit or quantum of light a particle of electromagnetic radiation that has zero rest mass and carries a quantum of energy. Ground State - The lowest energy state of a quantized system. Excited State - A state in which an atom has more energy than it does at its ground state. Emission-Line Spectru ...

... - A unit or quantum of light a particle of electromagnetic radiation that has zero rest mass and carries a quantum of energy. Ground State - The lowest energy state of a quantized system. Excited State - A state in which an atom has more energy than it does at its ground state. Emission-Line Spectru ...

Description of NOVA`s The Fabric of the Cosmos “Quantum Leap

... right now?” You ask, “If I look for the electron in this particular part of space, what is the likelihood I will find it there?” The equations of quantum mechanics are amazingly accurate, as long as you can accept it’s all about probability. - Physicists have no trouble accepting quantum mechanics, ...

... right now?” You ask, “If I look for the electron in this particular part of space, what is the likelihood I will find it there?” The equations of quantum mechanics are amazingly accurate, as long as you can accept it’s all about probability. - Physicists have no trouble accepting quantum mechanics, ...

influências da expansão do universo na evolução do - Cosmo-ufes

... wave function for the quantum part, and classical variables -variables which have values - for the classical part: (Ψ(t,q ...), X(t) ...). The Xs are somehow macroscopic. This is not spelled out very explicitly. The dynamics is not very precisely formulated either. It includes a Schrödinger equation ...

... wave function for the quantum part, and classical variables -variables which have values - for the classical part: (Ψ(t,q ...), X(t) ...). The Xs are somehow macroscopic. This is not spelled out very explicitly. The dynamics is not very precisely formulated either. It includes a Schrödinger equation ...

Teleportation - American University in Cairo

... best available hard drives. So this limits our ability to teleport objects in terms of equipment. • It will take more than 2,400 times the present age of the universe to access this amount of data for us to teleport ...

... best available hard drives. So this limits our ability to teleport objects in terms of equipment. • It will take more than 2,400 times the present age of the universe to access this amount of data for us to teleport ...

Gravitational Cat State and Stochastic Semiclassical Gravity*

... nearby test particle. The central quantity of importance for this inquiry is the energy density correlation. This corresponds to the noise kernel in stochastic semiclassical gravity theory [1,2], evaluated in the weak field nonrelativistic limit. In this limit, quantum fluctuations of the stress ene ...

... nearby test particle. The central quantity of importance for this inquiry is the energy density correlation. This corresponds to the noise kernel in stochastic semiclassical gravity theory [1,2], evaluated in the weak field nonrelativistic limit. In this limit, quantum fluctuations of the stress ene ...

PPT | 345.5 KB - Joint Quantum Institute

... Physicists supported by the PFC at the Joint Quantum Institute have developed a new source of “entangled” photons – fundamental units of light whose properties are so intertwined that if the condition of one is measured, the condition of the other is instantaneously known, even if the photons are th ...

... Physicists supported by the PFC at the Joint Quantum Institute have developed a new source of “entangled” photons – fundamental units of light whose properties are so intertwined that if the condition of one is measured, the condition of the other is instantaneously known, even if the photons are th ...

Open Questions in Physics

... 1. Where and what is dark matter? 2. How massive are neutrinos? 3. What are the implications of neutrino mass? 4. What are the origins of mass? 5. Why is gravity so weak? 6. Why is the universe made of matter and not antimatter? 7. Where do ultrahigh-energy cosmic rays come from? ...

... 1. Where and what is dark matter? 2. How massive are neutrinos? 3. What are the implications of neutrino mass? 4. What are the origins of mass? 5. Why is gravity so weak? 6. Why is the universe made of matter and not antimatter? 7. Where do ultrahigh-energy cosmic rays come from? ...

Weak measurements [1] Pre and Post selection in strong measurements

... We call the state |Ψi the ”pre-selected state” which is the state we prepare the system at and we call the state hΦ| the ”post-selected state” which is the state the system is at the end of the process. These two measurements are strong measurements. We notice that similarly to eq. (1) formalism the ...

... We call the state |Ψi the ”pre-selected state” which is the state we prepare the system at and we call the state hΦ| the ”post-selected state” which is the state the system is at the end of the process. These two measurements are strong measurements. We notice that similarly to eq. (1) formalism the ...

Computation, Quantum Theory, and You

... Theorem: Under any dynamical theory satisfying the symmetry and indifference axioms, the first Fourier transform makes the hidden variable “forget” whether it was at |i or |j. So after the second Fourier transform, it goes to |i half the time and |j half the time; thus with ½ probability we see ...

... Theorem: Under any dynamical theory satisfying the symmetry and indifference axioms, the first Fourier transform makes the hidden variable “forget” whether it was at |i or |j. So after the second Fourier transform, it goes to |i half the time and |j half the time; thus with ½ probability we see ...

The Learnability of Quantum States

... permanents of random matrices (the “PCC” and the “PGC”) Particular experiment we have in mind: Take a system of n identical photons with m=O(n2) modes. Put each photon in a known mode, then apply a Haar-random mm unitary transformation U: Then measure which modes have 1 or more photon in them ...

... permanents of random matrices (the “PCC” and the “PGC”) Particular experiment we have in mind: Take a system of n identical photons with m=O(n2) modes. Put each photon in a known mode, then apply a Haar-random mm unitary transformation U: Then measure which modes have 1 or more photon in them ...

Introduction to Quantum Systems

... Introduction to quantum physics and quantum systems with electromagnetic interaction (atoms, molecules and solids) and strong interaction (nucleons and particles) Course competences Specific 1. Understand the basis of quantum physics and the behaviour of identical particle systems 2. Demonstrate a s ...

... Introduction to quantum physics and quantum systems with electromagnetic interaction (atoms, molecules and solids) and strong interaction (nucleons and particles) Course competences Specific 1. Understand the basis of quantum physics and the behaviour of identical particle systems 2. Demonstrate a s ...

Wave Chaos in Electromagnetism and Quantum Mechanics

... conditions (for example the initial position and momentum of an atom in a gas). This is manifested in the “butterfly effect” in which a butterfly flapping it's wings in Brazil can eventually affect the weather here in College Park. However, many other interesting things involve waves, such as quantu ...

... conditions (for example the initial position and momentum of an atom in a gas). This is manifested in the “butterfly effect” in which a butterfly flapping it's wings in Brazil can eventually affect the weather here in College Park. However, many other interesting things involve waves, such as quantu ...

Quantum Clock of Radioactive Decay

... Salecker and Wigner and attempts were made to relate the time measured by such a quantum clock to the dwell time within a region. The dwell time seems to have emerged as an important definition with applications to physically measured times. After discussing the various time concepts, their connecti ...

... Salecker and Wigner and attempts were made to relate the time measured by such a quantum clock to the dwell time within a region. The dwell time seems to have emerged as an important definition with applications to physically measured times. After discussing the various time concepts, their connecti ...

Spring 2007 Colloquium Series Physics Department University of Oregon 4:00pm Thursdays, 100 Willamette

... After introducing Planck's relation between the frequency and energy of a quantized harmonic oscillator, and Einstein's famous use in 1905 of this relation for light oscillators, the formal study of quantized light is usually dropped until the student enters the second year of graduate studies, if i ...

... After introducing Planck's relation between the frequency and energy of a quantized harmonic oscillator, and Einstein's famous use in 1905 of this relation for light oscillators, the formal study of quantized light is usually dropped until the student enters the second year of graduate studies, if i ...

Two-State Vector Formalism

... between forward and backward evolving quantum states: we can always create a particular forward evolving quantum state, say |A = a. We measure A, and if the outcome is a different eigenvalue than a, we perform an appropriate transformation to the desired state. We cannot, however, create with certa ...

... between forward and backward evolving quantum states: we can always create a particular forward evolving quantum state, say |A = a. We measure A, and if the outcome is a different eigenvalue than a, we perform an appropriate transformation to the desired state. We cannot, however, create with certa ...

Fulltext

... the QD ensemble and figure 2b shows for the first time by us the red light filtered CL image. There is a clear distribution of sizes present, see regions shown inside the triangles. The larger particles show CL activity (e.g. region shown by the arrow in a and b and circled in c) but the smaller par ...

... the QD ensemble and figure 2b shows for the first time by us the red light filtered CL image. There is a clear distribution of sizes present, see regions shown inside the triangles. The larger particles show CL activity (e.g. region shown by the arrow in a and b and circled in c) but the smaller par ...

Quantum tomography or quantum state tomography is the process of reconstructing the quantum state (density matrix) for a source of quantum systems by measurements on the systems coming from the source. The source may be any device or system which prepares quantum states either consistently into quantum pure states or otherwise into general mixed states. To be able to uniquely identify the state, the measurements must be tomographically complete. That is, the measured operators must form an operator basis on the Hilbert space of the system, providing all the information about the state. Such a set of observations is sometimes called a quorum. In quantum process tomography on the other hand, known quantum states are used to probe a quantum process to find out how the process can be described. Similarly, quantum measurement tomography works to find out what measurement is being performed.The general principle behind quantum state tomography is that by repeatedly performing many different measurements on quantum systems described by identical density matrices, frequency counts can be used to infer probabilities, and these probabilities are combined with Born's rule to determine a density matrix which fits the best with the observations.This can be easily understood by making a classical analogy. Let us consider a harmonic oscillator (e.g. a pendulum). The position and momentum of the oscillator at any given point can be measured and therefore the motion can be completely described by the phase space. This is shown in figure 1. By performing this measurement for a large number of identical oscillators we get a possibility distribution in the phase space (figure 2). This distribution can be normalized (the oscillator at a given time has to be somewhere) and the distribution must be non-negative. So we have retrieved a function W(x,p) which gives a description of the chance of finding the particle at a given point with a given momentum. For quantum mechanical particles the same can be done. The only difference is that the Heisenberg’s uncertainty principle mustn’t be violated, meaning that we cannot measure the particle’s momentum and position at the same time. The particle’s momentum and its position are called quadratures (see Optical phase space for more information) in quantum related states. By measuring one of the quadratures of a large number of identical quantum states will give us a probability density corresponding to that particular quadrature. This is called the marginal distribution, pr(X) or pr(P) (see figure 3). In the following text we will see that this probability density is needed to characterize the particle’s quantum state, which is the whole point of quantum tomography.