Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1012.4557 · Physical Review E

Real-space renormalization group for the transverse-field Ising model in two and three dimensions

Ryoji Miyazaki, Hidetoshi Nishimori, Gerardo Ortíz

Published May 2, 2011• 15 citations
arXivHTMLPDF

Abstract

The two- and three-dimensional transverse-field Ising models with ferromagnetic exchange interactions are analyzed by means of the real-space renormalization-group method. The basic strategy is a generalization of a method developed for the one-dimensional case, which exploits the exact invariance of the model under renormalization and is known to give the exact values of the critical point and critical exponent ν. The resulting values of the critical exponent ν in two and three dimensions are in good agreement with those for the classical Ising model in three and four dimensions. To the best of our knowledge, this is the first example in which a real-space renormalization group on (2+1)- and (3+1)-dimensional Bravais lattices yields accurate estimates of the critical exponents.

DOI
10.1103/physreve.83.051103

Related papers

Real-space renormalization-group approach to the random transverse-field Ising model in finite dimensions

Ryoji Miyazaki, Hidetoshi Nishimori

The transverse-field Ising models with random exchange interactions in finite dimensions are investigated by means of a real-space renormalization-group method. The scheme yields the exact values of the critical point and critical exponent $\ensuremath{\nu}$ in one dimension and some previous results in the case of random ferromagnetic interactions are reproduced in two and three dimensions. We apply the scheme to spin glasses in transverse fields in two and three dimensions, which have not been analyzed very extensively. The phase diagrams and the critical exponent $\ensuremath{\nu}$ are obtained and evidence for the existence of an infinite-randomness fixed point in these models is found.

arXiv:1210.5053•Physical Review E•Mar 25, 2013•24 citations

Precise estimation of critical exponents from real-space renormalization group analysis

Aleksander Kubica, Beni Yoshida

We develop a novel real-space renormalization group (RG) scheme which accurately estimates correlation length exponent $ν$ near criticality of higher-dimensional quantum Ising and Potts models in a transverse field. Our method is remarkably simple (often analytical), grouping only a few spins into a block spin so that renormalized Hamiltonian has a closed form. A previous difficulty of spatial anisotropy and unwanted terms is avoided by incorporating rotational invariance and internal $\mathbb{Z}_q$ symmetries of the Hamiltonian. By applying this scheme to the (2+1)-dim Ising model on a triangular lattice and solving an analytical RG equation, we obtain $ν\approx 0.6300$. This value is within statistical errors of the current best Monte-Carlo result, 25th-order high-temperature series expansions, $ϕ^4$-theory estimation which considers up to seven-loop corrections and experiments performed in low-Earth orbits. We also apply the scheme to higher-dimensional Potts models for which ordinary Monte-Carlo methods are not effective due to strong hysteresis and suppression of quantum fluctuation in a weak first-order phase transition.

arXiv:1402.0619•Feb 4, 2014•3 citations

ランダム量子スピン系の実空間くりこみ群による解析

涼二 宮崎, Ryoji Miyazaki

The present thesis investigates phase transitions and critical phenomena in the random transverse-field Ising models by means of a real-space renormalization-group method.The analysis is intended to examine the presence of infinite-randomness fixed points in the models in a renormalization-group picture.Infinite-randomness fixed points are concerned with peculiar critical phenomena, which have been established in a study of the one-dimensional random transverse-field Ising model.Subsequent studies have conjectured the presence of the fixed point in some cases.The thesis mainly examines such two cases: the two-and three-dimensional Ising spin glasses in a transverse field and the one-dimensional Ising spin glass with the power-law interaction in a transverse field.The latter is not directly tackled.Instead, we introduce and analyze the hierarchical model which is expected to show similar critical phenomena.A real-space renormalization-group method is exploited in the thesis.We develop the method in a model without randomness first.The method reproduces some previously known results of transition points and critical exponents in pure and disordered cases.The spin-glass models mentioned above are investigated with the method.We find evidence of the presence of infinite-randomness fixed points in these cases as a result, which supports the conjectures.

•Mar 1, 2014•0 citations

Infinite-disorder scaling of random quantum magnets in three and higher dimensions

István A. Kovács, Ferenc Iglói

Using a very efficient numerical algorithm of the strong disorder renormalization group method, we have extended the investigations about the critical behavior of the random transverse-field Ising model in three and four dimensions, as well as for Erd\ifmmode \mbox{\H{o}}\else \H{o}\fi{}s-R\'enyi random graphs, which represent infinite dimensional lattices. In all studied cases, an infinite disorder quantum critical point is identified, which ensures that the applied method is asymptotically correct and the calculated critical exponents tend to the exact values for large scales. We have found that the critical exponents are independent of the form of (ferromagnetic) disorder and they vary smoothly with the dimensionality.

arXiv:1010.2344•Physical Review B•May 31, 2011•88 citations

The random transverse field Ising model ind= 2: analysis via boundary strong disorder renormalization

Cécile Monthus, Thomas Garel

To avoid the complicated topology of surviving clusters induced by standard strong disorder RG in dimension d > 1, we introduce a modified procedure called 'boundary strong disorder RG' where the order of decimations is chosen a priori . We apply this modified procedure numerically to the random transverse field Ising model in dimension d = 2. We find that the location of the critical point, the activated exponent ψ ≃ 0.5 of the infinite-disorder scaling, and the finite-size correlation exponent ν FS ≃ 1.3 are compatible with the values obtained previously using standard strong disorder RG. Our conclusion is thus that strong disorder RG is very robust with respect to changes in the order of decimations. In addition, we analyze the RG flows within the two phases in more detail, to show explicitly the presence of various correlation length exponents: we measure the typical correlation exponent ν typ ≃ 0.64 for the disordered phase (this value is very close to the correlation exponent of the pure two-dimensional quantum Ising model), and the typical exponent ν h ≃ 1 for the ordered phase. These values satisfy the relations between critical exponents imposed by the expected finite-size scaling properties at infinite-disorder critical points. We also measure, within the disordered phase, the fluctuation exponent ω ≃ 0.35 which is compatible with the directed polymer exponent in (1 + 1) dimensions.

arXiv:1206.6997•Journal of Statistical Mechanics Theory and Experiment•Sep 28, 2012•9 citations

Symmetry-respecting real-space renormalization for the quantum Ashkin-Teller model

Aroon O’Brien, Stephen D. Bartlett, Andrew C. Doherty +1 more

We use a simple real-space renormalization-group approach to investigate the critical behavior of the quantum Ashkin-Teller model, a one-dimensional quantum spin chain possessing a line of criticality along which critical exponents vary continuously. This approach, which is based on exploiting the on-site symmetry of the model, has been shown to be surprisingly accurate for predicting some aspects of the critical behavior of the quantum transverse-field Ising model. Our investigation explores this approach in more generality, in a model in which the critical behavior has a richer structure but which reduces to the simpler Ising case at a special point. We demonstrate that the correlation length critical exponent as predicted from this real-space renormalization-group approach is in broad agreement with the corresponding results from conformal field theory along the line of criticality. Near the Ising special point, the error in the estimated critical exponent from this simple method is comparable to that of numerically intensive simulations based on much more sophisticated methods, although the accuracy decreases away from the decoupled Ising model point.

arXiv:1507.00038•Physical Review E•Oct 29, 2015•15 citations
The two- and three-dimensional transverse-field Ising models with ferromagnetic exchange interactions are analyzed by means of the real-space renormalization-group method. The basic strategy is a generalization of a method developed for the one-dimensional case, which exploits the exact invariance of the model under renormalization and is known to give the exact values of the critical point and critical exponent ν. The resulting values of the critical exponent ν in two and three dimensions are in good agreement with those for the classical Ising model in three and four dimensions. To the best of our knowledge, this is the first example in which a real-space renormalization group on (2+1)- and (3+1)-dimensional Bravais lattices yields accurate estimates of the critical exponents.
The transverse-field Ising models with random exchange interactions in finite dimensions are investigated by means of a real-space renormalization-group method. The scheme yields the exact values of the critical point and critical exponent $\ensuremath{\nu}$ in one dimension and some previous results in the case of random ferromagnetic interactions are reproduced in two and three dimensions. We apply the scheme to spin glasses in transverse fields in two and three dimensions, which have not been analyzed very extensively. The phase diagrams and the critical exponent $\ensuremath{\nu}$ are obtained and evidence for the existence of an infinite-randomness fixed point in these models is found.
We develop a novel real-space renormalization group (RG) scheme which accurately estimates correlation length exponent ννν near criticality of higher-dimensional quantum Ising and Potts models in a transverse field. Our method is remarkably simple (often analytical), grouping only a few spins into a block spin so that renormalized Hamiltonian has a closed form. A previous difficulty of spatial anisotropy and unwanted terms is avoided by incorporating rotational invariance and internal Zq\mathbb{Z}_qZq​ symmetries of the Hamiltonian. By applying this scheme to the (2+1)-dim Ising model on a triangular lattice and solving an analytical RG equation, we obtain ν≈0.6300ν\approx 0.6300ν≈0.6300. This value is within statistical errors of the current best Monte-Carlo result, 25th-order high-temperature series expansions, ϕ4ϕ^4ϕ4-theory estimation which considers up to seven-loop corrections and experiments performed in low-Earth orbits. We also apply the scheme to higher-dimensional Potts models for which ordinary Monte-Carlo methods are not effective due to strong hysteresis and suppression of quantum fluctuation in a weak first-order phase transition.
The present thesis investigates phase transitions and critical phenomena in the random transverse-field Ising models by means of a real-space renormalization-group method.The analysis is intended to examine the presence of infinite-randomness fixed points in the models in a renormalization-group picture.Infinite-randomness fixed points are concerned with peculiar critical phenomena, which have been established in a study of the one-dimensional random transverse-field Ising model.Subsequent studies have conjectured the presence of the fixed point in some cases.The thesis mainly examines such two cases: the two-and three-dimensional Ising spin glasses in a transverse field and the one-dimensional Ising spin glass with the power-law interaction in a transverse field.The latter is not directly tackled.Instead, we introduce and analyze the hierarchical model which is expected to show similar critical phenomena.A real-space renormalization-group method is exploited in the thesis.We develop the method in a model without randomness first.The method reproduces some previously known results of transition points and critical exponents in pure and disordered cases.The spin-glass models mentioned above are investigated with the method.We find evidence of the presence of infinite-randomness fixed points in these cases as a result, which supports the conjectures.
Using a very efficient numerical algorithm of the strong disorder renormalization group method, we have extended the investigations about the critical behavior of the random transverse-field Ising model in three and four dimensions, as well as for Erd\ifmmode \mbox{\H{o}}\else \H{o}\fi{}s-R\'enyi random graphs, which represent infinite dimensional lattices. In all studied cases, an infinite disorder quantum critical point is identified, which ensures that the applied method is asymptotically correct and the calculated critical exponents tend to the exact values for large scales. We have found that the critical exponents are independent of the form of (ferromagnetic) disorder and they vary smoothly with the dimensionality.
To avoid the complicated topology of surviving clusters induced by standard strong disorder RG in dimension d > 1, we introduce a modified procedure called 'boundary strong disorder RG' where the order of decimations is chosen a priori . We apply this modified procedure numerically to the random transverse field Ising model in dimension d = 2. We find that the location of the critical point, the activated exponent ψ ≃ 0.5 of the infinite-disorder scaling, and the finite-size correlation exponent ν FS ≃ 1.3 are compatible with the values obtained previously using standard strong disorder RG. Our conclusion is thus that strong disorder RG is very robust with respect to changes in the order of decimations. In addition, we analyze the RG flows within the two phases in more detail, to show explicitly the presence of various correlation length exponents: we measure the typical correlation exponent ν typ ≃ 0.64 for the disordered phase (this value is very close to the correlation exponent of the pure two-dimensional quantum Ising model), and the typical exponent ν h ≃ 1 for the ordered phase. These values satisfy the relations between critical exponents imposed by the expected finite-size scaling properties at infinite-disorder critical points. We also measure, within the disordered phase, the fluctuation exponent ω ≃ 0.35 which is compatible with the directed polymer exponent in (1 + 1) dimensions.
We use a simple real-space renormalization-group approach to investigate the critical behavior of the quantum Ashkin-Teller model, a one-dimensional quantum spin chain possessing a line of criticality along which critical exponents vary continuously. This approach, which is based on exploiting the on-site symmetry of the model, has been shown to be surprisingly accurate for predicting some aspects of the critical behavior of the quantum transverse-field Ising model. Our investigation explores this approach in more generality, in a model in which the critical behavior has a richer structure but which reduces to the simpler Ising case at a special point. We demonstrate that the correlation length critical exponent as predicted from this real-space renormalization-group approach is in broad agreement with the corresponding results from conformal field theory along the line of criticality. Near the Ising special point, the error in the estimated critical exponent from this simple method is comparable to that of numerically intensive simulations based on much more sophisticated methods, although the accuracy decreases away from the decoupled Ising model point.