Qubit phase space:SU(n)coherent-statePrepresentations
| العنوان: | Qubit phase space:SU(n)coherent-statePrepresentations |
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| المؤلفون: | Peter D. Drummond, D. W. Barry |
| المصدر: | Physical Review A. 78 |
| بيانات النشر: | American Physical Society (APS), 2008. |
| سنة النشر: | 2008 |
| مصطلحات موضوعية: | Physics, Canonical ensemble, Quantum decoherence, Phase space, Quantum mechanics, Qubit, Master equation, Time evolution, Coherent states, Ising model, Statistical physics, Atomic and Molecular Physics, and Optics |
| الوصف: | We introduce a phase-space representation for qubits and spin models. The technique uses an SUn coherent-state basis and can equally be used for either static or dynamical simulations. We review previously known definitions and operator identities, and show how these can be used to define an off-diagonal, positive phase-space representation analogous to the positive-P function. As an illustration of the phase-space method, we use the example of the Ising model, which has exact solutions for the finite-temperature canonical ensemble in two dimensions. We show how a canonical ensemble for an Ising model of arbitrary structure can be efficiently simulated using SU2 or atomic coherent states. The technique utilizes a transformation from a canonical imaginary-time weighted simulation to an equivalent unweighted real-time simulation. The results are compared to the exactly soluble two-dimensional case. We note that Ising models in one, two, or three dimensions are potentially achievable experimentally as a lattice gas of ultracold atoms in optical lattices. The technique is not restricted to canonical ensembles or to Ising-like couplings. It is also able to be used for real-time evolution and for systems whose time evolution follows a master equation describing decoherence and coupling to external reservoirs. The case of SUn phase space is used to describe n-level systems. In general, the requirement that time evolution be stochastic corresponds to a restriction to Hamiltonians and master equations that are quadratic in the group generators or generalized spin operators. |
| تدمد: | 1094-1622 1050-2947 |
| DOI: | 10.1103/physreva.78.052108 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::b6ee3f5692e4423bd27d82fb1c92fbf9 https://doi.org/10.1103/physreva.78.052108 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi...........b6ee3f5692e4423bd27d82fb1c92fbf9 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 10941622 10502947 |
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| DOI: | 10.1103/physreva.78.052108 |