Quantum-state estimation
... Deviations between actually detected w( j ) and the true statistics w r ( j ) spoil the positivity of the reconstructed density matrix. There are at least the following imperfections of the detected statistics w( j ), which should always be taken into account: ~i! the sampling error caused by the li ...
... Deviations between actually detected w( j ) and the true statistics w r ( j ) spoil the positivity of the reconstructed density matrix. There are at least the following imperfections of the detected statistics w( j ), which should always be taken into account: ~i! the sampling error caused by the li ...
... self-adjoint may still have a canonical self-adjoint extension. Such is the case for non-negative symmetric operators (or more generally, operators which are bounded below). These operators always have a canonically defined Friedrichs extension and for these operators we can define a canonical funct ...
Physics 2170
... They proposed a way out: Electrons actually always know their spin in every direction but experiments can only get the limited knowledge allowed by quantum mechanics. A better theory would allow one to get access to this information. This is called a hidden variable theory. In 1964, J.S Bell proved ...
... They proposed a way out: Electrons actually always know their spin in every direction but experiments can only get the limited knowledge allowed by quantum mechanics. A better theory would allow one to get access to this information. This is called a hidden variable theory. In 1964, J.S Bell proved ...
Supplementary notes on units
... physical law relating mass, length, and time, that would enable us to use the units of one to measure the other. However, there is no reason to choose mass, length, and time to be the three building blocks for our units. We could instead choose any three other quantities, provided any combination of ...
... physical law relating mass, length, and time, that would enable us to use the units of one to measure the other. However, there is no reason to choose mass, length, and time to be the three building blocks for our units. We could instead choose any three other quantities, provided any combination of ...
THE DEFECT EFFECT ON THE ELECTRONIC CONDUCTANCE IN H. S. Ashour
... the central element of the binomial tailored quantum wire, and keeping the other elements and the spacing between the Dirac delta function potentials constant, on the electronic conductance through the BTQW. First, we consider the strength defect does not exceed ±5% of the Dirac delta function poten ...
... the central element of the binomial tailored quantum wire, and keeping the other elements and the spacing between the Dirac delta function potentials constant, on the electronic conductance through the BTQW. First, we consider the strength defect does not exceed ±5% of the Dirac delta function poten ...
Cosmological Singularities in String Theory
... • The event horizon is not well defined in the quantum theory. • The qualitative behavior of hyperbolic black holes with different mass is correlated with behavior of the scalars in the field theory. • To change the time slices in the bulk, you need a field dependent time reparameterization in the ...
... • The event horizon is not well defined in the quantum theory. • The qualitative behavior of hyperbolic black holes with different mass is correlated with behavior of the scalars in the field theory. • To change the time slices in the bulk, you need a field dependent time reparameterization in the ...
critical fields of thin superconducting films
... The impurity concentration, i.e., the relation between the mean free path and the other parameters ~ 0 and L of our problem, substantially influences the behavior and value of the critical field. A. Let us consider the casr~ of a mean free path which is large in comparison with the BCS correlation p ...
... The impurity concentration, i.e., the relation between the mean free path and the other parameters ~ 0 and L of our problem, substantially influences the behavior and value of the critical field. A. Let us consider the casr~ of a mean free path which is large in comparison with the BCS correlation p ...
Indistinguishable Particles in Quantum Mechanics: An Introduction
... internal states are not a good criterium, as the dynamics can in general affect the internal degrees of freedom of the particles. The same is valid for their momentum or other dynamical variables. But their spatial location can actually be used to distinguish them, as shown in Fig. 1. Let us imagine ...
... internal states are not a good criterium, as the dynamics can in general affect the internal degrees of freedom of the particles. The same is valid for their momentum or other dynamical variables. But their spatial location can actually be used to distinguish them, as shown in Fig. 1. Let us imagine ...
Strong-Disorder Fixed Point in the Dissipative Random Transverse-Field Ising Model
... quantities above a temperature T Lz . L is a characteristic length scale above which the ground state displays a nonvanishing magnetization, as predicted by the smeared transition scenario [14], and that we determined to increase exponentially with the inverse strength of the dissipative c ...
... quantities above a temperature T Lz . L is a characteristic length scale above which the ground state displays a nonvanishing magnetization, as predicted by the smeared transition scenario [14], and that we determined to increase exponentially with the inverse strength of the dissipative c ...
Dynamical Phase Transitions in Quantum Systems
... in the second case. It is possible therefore that some wavefunctions k of the system align with the scattering wavefunctions of the environment while the other states decouple (more or less) from the environment. This phenomenon, called resonance trapping, is nothing but width bifurcation caused b ...
... in the second case. It is possible therefore that some wavefunctions k of the system align with the scattering wavefunctions of the environment while the other states decouple (more or less) from the environment. This phenomenon, called resonance trapping, is nothing but width bifurcation caused b ...
Two-stage Rydberg charge exchange in a strong magnetic field 兲
... Recent experiments have demonstrated the formation of antihydrogen 共H̄兲 共e.g., see Refs. 关1,2兴兲. In both experiments, cold antiprotons, p̄’s, traverse a cold positron, e+, plasma; a p̄ can capture one of the e+’s during its brief time in the plasma. Presumably 关3–5兴, the H̄ is formed through three b ...
... Recent experiments have demonstrated the formation of antihydrogen 共H̄兲 共e.g., see Refs. 关1,2兴兲. In both experiments, cold antiprotons, p̄’s, traverse a cold positron, e+, plasma; a p̄ can capture one of the e+’s during its brief time in the plasma. Presumably 关3–5兴, the H̄ is formed through three b ...
Experiment sees the arrow of time Experiment sees the arrow of time
... The laws of electrodynamics and the strong interaction preserve CP symmetry to great accuracy. However, it is known that weak interactions do not conserve CP symmetry. This was confirmed experimentally by Christenson, Cronin, Fitch and Turlay in 1964 when they measured rare (1-in-500) decays of long ...
... The laws of electrodynamics and the strong interaction preserve CP symmetry to great accuracy. However, it is known that weak interactions do not conserve CP symmetry. This was confirmed experimentally by Christenson, Cronin, Fitch and Turlay in 1964 when they measured rare (1-in-500) decays of long ...
Parallel Universes
... 1.This type of parallel universes is sort of a catch-all for other mathematical structures which we can conceive of, but which we don't observe as physical realities in our universe. 2.The Level 4 parallel universes are ones which are governed by different equations from those that govern our univer ...
... 1.This type of parallel universes is sort of a catch-all for other mathematical structures which we can conceive of, but which we don't observe as physical realities in our universe. 2.The Level 4 parallel universes are ones which are governed by different equations from those that govern our univer ...
COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC.
... tails of how they are realized. Similarly, the properties of a qubit are independent of its specific physical representation as the spin of an atomic nucleus, say, or the polarization of a photon of light. A bit is described by its state, 0 or 1. Likewise, a qubit is described by its quantum state. ...
... tails of how they are realized. Similarly, the properties of a qubit are independent of its specific physical representation as the spin of an atomic nucleus, say, or the polarization of a photon of light. A bit is described by its state, 0 or 1. Likewise, a qubit is described by its quantum state. ...