Uncomputability of phase diagrams

Autor: James D. Watson, Toby S. Cubitt, Johannes Bausch
Přispěvatelé: Bausch, Johannes [0000-0003-3189-9162], Watson, James D. [0000-0002-6077-4898], Apollo - University of Cambridge Repository, Watson, James D [0000-0002-6077-4898]
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Work (thermodynamics)
639/705/1041
03D35
68Q17
81V70
82B26

Science
math-ph
FOS: Physical sciences
General Physics and Astronomy
02 engineering and technology
Parameter space
639/766/259
Computer Science::Digital Libraries
01 natural sciences
Measure (mathematics)
General Biochemistry
Genetics and Molecular Biology

Article
symbols.namesake
math.MP
quant-ph
639/766/119/2795
0103 physical sciences
Information theory and computation
129
010306 general physics
Mathematical Physics
Mathematical physics
Phase diagram
Physics
Quantum Physics
Multidisciplinary
Zero (complex analysis)
Mathematical Physics (math-ph)
General Chemistry
Function (mathematics)
021001 nanoscience & nanotechnology
Applied mathematics
Condensed Matter - Other Condensed Matter
Phase transitions and critical phenomena
cond-mat.other
symbols
Spectral gap
Quantum Physics (quant-ph)
0210 nano-technology
Hamiltonian (quantum mechanics)
Other Condensed Matter (cond-mat.other)
Zdroj: Nature Communications
Nature Communications, Vol 12, Iss 1, Pp 1-8 (2021)
ISSN: 2041-1723
Popis: The phase diagram of a material is of central importance in describing the properties and behaviour of a condensed matter system. In this work, we prove that the task of determining the phase diagram of a many-body Hamiltonian is in general uncomputable, by explicitly constructing a continuous one-parameter family of Hamiltonians H(φ), where \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi \in {\mathbb{R}}$$\end{document}φ∈R, for which this is the case. The H(φ) are translationally-invariant, with nearest-neighbour couplings on a 2D spin lattice. As well as implying uncomputablity of phase diagrams, our result also proves that undecidability can hold for a set of positive measure of a Hamiltonian’s parameter space, whereas previous results only implied undecidability on a zero measure set. This brings the spectral gap undecidability results a step closer to standard condensed matter problems, where one typically studies phase diagrams of many-body models as a function of one or more continuously varying real parameters, such as magnetic field strength or pressure.
Phase diagrams describe how a system changes phenomenologically as an external parameter, such as a magnetic field strength, is varied. Here, the authors prove that in general such a phase diagram is uncomputable, by explicitly constructing a one-parameter Hamiltonian for which this is the case.
Databáze: OpenAIRE