Entanglement in Open Quantum Systems
... compared to the time scale needed to perform the actual algorithmic task. Since entanglement is a manifestation of coherent superpositions of many-particle eigenstates of a quantum register, it is clear that decoherence will be detrimental for quantum entanglement, and a quantitative theory to asses ...
... compared to the time scale needed to perform the actual algorithmic task. Since entanglement is a manifestation of coherent superpositions of many-particle eigenstates of a quantum register, it is clear that decoherence will be detrimental for quantum entanglement, and a quantitative theory to asses ...
5, 4023 (2014)
... Collective excitations. It is well known that various physical quantities may change dramatically across a quantum critical point38. As a particular example, we investigate the quadrupole collective excitation of a SO-coupled BEC. In BECs without SO coupling, the quadrupole excitation frequency only ...
... Collective excitations. It is well known that various physical quantities may change dramatically across a quantum critical point38. As a particular example, we investigate the quadrupole collective excitation of a SO-coupled BEC. In BECs without SO coupling, the quadrupole excitation frequency only ...
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... interpretation of mixtures, but does not necessarily follow without that interpretation. And, he continues, the ignorance interpretation of mixtures equivocates on the nature of quantum states, as expressed by means of the statistical operator formalism: A quantum mixed state so expressed should no ...
... interpretation of mixtures, but does not necessarily follow without that interpretation. And, he continues, the ignorance interpretation of mixtures equivocates on the nature of quantum states, as expressed by means of the statistical operator formalism: A quantum mixed state so expressed should no ...
referring
... operator equation of motion兲. He noted that in the classical case a solution can be obtained by expressing x(t) as a Fourier series, substitution of which into the equation of motion leads 共in special cases兲 to a set of recursion relations for the Fourier coefficients. In the quantum theory, Heisenb ...
... operator equation of motion兲. He noted that in the classical case a solution can be obtained by expressing x(t) as a Fourier series, substitution of which into the equation of motion leads 共in special cases兲 to a set of recursion relations for the Fourier coefficients. In the quantum theory, Heisenb ...
Spin Flips and Quantum Information for Antiparallel Spins
... is not unitary but antiunitary. Thus there is no physical operation which could implement such a transformation. But then a couple of question arise. First, why is it still the case that a single spin polarized along n defines the direction as well as a single spin polarized in the opposite directi ...
... is not unitary but antiunitary. Thus there is no physical operation which could implement such a transformation. But then a couple of question arise. First, why is it still the case that a single spin polarized along n defines the direction as well as a single spin polarized in the opposite directi ...
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... Quantum systems are defined by attributes, such as position, momentum, angular momentum, and energy or Hamiltonian. These attributes—and thus the numerical particulars of their eigenvalues and eigenfunctions—are objective properties of the system. The value assumed by an attribute is not an objectiv ...
... Quantum systems are defined by attributes, such as position, momentum, angular momentum, and energy or Hamiltonian. These attributes—and thus the numerical particulars of their eigenvalues and eigenfunctions—are objective properties of the system. The value assumed by an attribute is not an objectiv ...
Particle in a box
In quantum mechanics, the particle in a box model (also known as the infinite potential well or the infinite square well) describes a particle free to move in a small space surrounded by impenetrable barriers. The model is mainly used as a hypothetical example to illustrate the differences between classical and quantum systems. In classical systems, for example a ball trapped inside a large box, the particle can move at any speed within the box and it is no more likely to be found at one position than another. However, when the well becomes very narrow (on the scale of a few nanometers), quantum effects become important. The particle may only occupy certain positive energy levels. Likewise, it can never have zero energy, meaning that the particle can never ""sit still"". Additionally, it is more likely to be found at certain positions than at others, depending on its energy level. The particle may never be detected at certain positions, known as spatial nodes.The particle in a box model provides one of the very few problems in quantum mechanics which can be solved analytically, without approximations. This means that the observable properties of the particle (such as its energy and position) are related to the mass of the particle and the width of the well by simple mathematical expressions. Due to its simplicity, the model allows insight into quantum effects without the need for complicated mathematics. It is one of the first quantum mechanics problems taught in undergraduate physics courses, and it is commonly used as an approximation for more complicated quantum systems.