dorsal/arxiv
View SchemaExact Classical Effective Potential
| Authors | J H Samson |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/9905089 |
| URL | https://arxiv.org/abs/quant-ph/9905089 |
| Journal | Proceedings of Sixth International Conference on Path Integrals from peV to TeV, Firenze, eds R Casalbuoni et al (World Scientific 1999), 550-553 |
Abstract
A quantum spin system can be modelled by an equivalent classical system, with an effective Hamiltonian obtained by integrating all non-zero frequency modes out of the path integral. The effective Hamiltonian H_eff(S_i) derived from the coherent-state integral is highly singular: the quasiprobability density exp(-beta H_eff), a Wigner function, imposes quantisation through derivatives of delta functions. This quasiprobability is the distribution of the time-averaged lower symbol of the spin in the coherent-state integral. We relate the quantum Monte Carlo minus-sign problem to the non-positivity of this quasiprobability, both analytically and by Monte Carlo integration.
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"abstract": "A quantum spin system can be modelled by an equivalent classical system, with\nan effective Hamiltonian obtained by integrating all non-zero frequency modes\nout of the path integral. The effective Hamiltonian H_eff(S_i) derived from the\ncoherent-state integral is highly singular: the quasiprobability density\nexp(-beta H_eff), a Wigner function, imposes quantisation through derivatives\nof delta functions. This quasiprobability is the distribution of the\ntime-averaged lower symbol of the spin in the coherent-state integral. We\nrelate the quantum Monte Carlo minus-sign problem to the non-positivity of this\nquasiprobability, both analytically and by Monte Carlo integration.",
"arxiv_id": "quant-ph/9905089",
"authors": [
"J H Samson"
],
"categories": [
"quant-ph",
"cond-mat.stat-mech"
],
"journal_ref": "Proceedings of Sixth International Conference on Path Integrals\n from peV to TeV, Firenze, eds R Casalbuoni et al (World Scientific 1999),\n 550-553",
"title": "Exact Classical Effective Potential",
"url": "https://arxiv.org/abs/quant-ph/9905089"
},
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