Phase transitions are among the most striking phenomena of nature. While continuously changing a parameter, like the temperature, the system shows singular behavior at the transition point while a substantial change in the physical properties of the system is found. At a continuous phase transition the degrees of freedom become macroscopically correlated at the critical point, thus the emerging critical singularities are powerful manifestations of collective phenomena. The most impressive property of continuous phase transitions is their universality: the critical behavior is often insensitive to microscopic details, depending only on global characteristics, such as the number of spatial dimensions, the range of interactions and the symmetries of the system. Consequently, it is often sufficient to study a simplified model instead of a realistic system in order to obtain its critical properties. Spatial inhomogeneities, such as dislocations or impurities are inevitable features of realistic systems. Do we have to incorporate also disorder in the models to describe critical phenomena at large scales then, or is it just one of the many unimportant microscopic details? In our research we show that disorder may dramatically change the critical behavior known in the clean, disorder-free system, leading to exotic phenomena.
Related Publications
- R. Juhász and I. A. Kovács, Smoothly vanishing density in the contact process by an interplay of disorder and long-distance dispersal, SciPost Physics Core, 7, 044 [arXiv]
- H. S. Ansell and I. A. Kovács (2024) Unveiling universal aspects of the cellular anatomy of the brain, Communications Physics, 7, 184 [arXiv]
- I. A. Kovács (2024) Quantum entanglement in the multicritical disordered Ising model, Phys. Rev. B, 109, 214202 [arXiv]
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H. S. Ansell, S. J. Frank, I. A. Kovács (2023) Cluster tomography in percolation, Phys. Rev. Research, 5, 043218 [arXiv]
- R. T. C. Chepuri and I. A. Kovács (2023) Complex quantum network models from spin clusters, Communications Physics, 6, 271 [arXiv]
- T. Pető, F. Iglói and I. A. Kovács (2023) Random Ising chain in transverse and longitudinal fields: Strong disorder RG study, Condensed Matter Physics,vol. 26, No. 1, 13101. Special issue – Complexity and collective behaviour: Solids, Fields, and Data (dedicated to Betrand Berche on his 60th birthday) [arXiv]
- J. S. Zou, H. S. Ansell and I. A. Kovács (2022) Multipartite entanglement in the random Ising chain, Phys. Rev. B 106, 054201 [arXiv]
- I. A. Kovács (2022) Quantum multicritical point in the two- and three-dimensional random transverse-field Ising model, Phys. Rev. Research 4, 013072 [arXiv]
- I. A. Kovács and F. Iglói (2022) Geometry of rare regions behind Griffiths singularities in random quantum magnets, Scientific Reports 12, 1074 [arXiv] [Research Square]
- I. A. Kovács, T. Pető and F. Iglói (2021) Extreme statistics of the excitations in the random transverse Ising chain, Phys. Rev. Research 3, 033140 [arXiv]
- I. A. Kovács and R. Juhász (2020) Emergence of disconnected clusters in heterogeneous complex systems, Scientific Reports 10, 21874 [arXiv]
- R. Juhász and I. A. Kovács (2020) Scaling of local persistence in the disordered contact process, Phys. Rev. E 102, 012108 [arXiv]
- R. Juhász and I. A. Kovács (2020) Population boundary across an environmental gradient: Effects of quenched disorder, Physical Review Research 2 023123 [arXiv]
- G. Roósz, I. A. Kovács and F. Iglói (2020) Entanglement entropy of random partitioning, Eur. Phys. J. B 93:8 [arXiv]
- F. Iglói and I. A. Kovács (2018) Transverse-spin correlations of the random transverse-field Ising model, Phys. Rev. B 97, 094205 [arXiv]
- R. Juhász, I. A. Kovács, G. Roósz and F. Iglói (2017) Entanglement between random and clean quantum spin chains, J. Phys. A: Math. Theor, 50 324003 [arXiv]
- I. A. Kovács, R. Juhász and F. Iglói (2016) Long-range random transverse-field Ising model in three dimensions, Phys. Rev. B 93 184203 [arXiv]
- I. A. Kovács and A.-L. Barabási (2015) Network science: Destruction perfected. Nature 524, 38-39.
- R. Juhász, I. A. Kovács and F. Iglói (2015) Long-range epidemic spreading in a random environment, Phys. Rev. E 91 032815 [arXiv]
- R. Juhász, I. A. Kovács and F. Iglói (2014) Random transverse-field Ising chain with long-range interactions, Europhysics Letters 107 47008 (editor’s choice) [arXiv]
- I. A. Kovács, J.-Ch. Angles d’Auriac and F. Iglói (2014) Excess entropy and central charge of the two-dimensional random-bond Potts model in the large-Q limit, J. Stat. Mech. P09019 [arXiv]
- I. A. Kovács and F. Iglói (2014) Corner contribution to percolation cluster numbers in three dimensions, Phys. Rev. B 89 174202 [arXiv]
- I. A. Kovács, E. M. Elci, M. Weigel and F. Iglói (2014) Corner contribution to cluster numbers in the Potts model, Phys. Rev. B 89 064421 [arXiv]
- F. Iglói and I. Kovács (2014) Végtelenül rendezetlen kritikus viselkedés Fizikai Szemle. 2014/11. p. 366-371 (in hungarian, “Infinitely disordered critical behavior”)
- R. Juhász and I. A. Kovács (2013) Infinite randomness critical behavior of the contact process on networks with long-ranged connections, J. Stat. Mech. P06003 [arXiv]
- I. A. Kovács and F. Iglói (2013) Boundary critical phenomena of the random transverse Ising model in D>=2 dimensions, Phys. Rev. B 87 024204 [arXiv]
- I. Kovács (2013) ‘Infinitely Disordered Critical Behavior in Higher Dimensional Quantum Systems’ Ph. D. dissertation, Supervisor: Prof. Ferenc Iglói, consultant: Prof. emer. Péter Szépfalusy, Eötvös Loránd University of Sciences (ELTE), Wigner RCP SZFKI, Budapest, Hungary
- I. A. Kovács, F. Iglói and J. Cardy (2012) Corner contribution to percolation cluster numbers, Phys. Rev. B 86, 214203 [arXiv]
- I. A. Kovács and F. Iglói (2012) Universal logarithmic terms in the entanglement entropy of 2d, 3d and 4d random transverse-field Ising models, Europhysics Letters 97 67009 [arXiv]
- A. Mihalik, A. S. Kaposi, I. A. Kovacs, T. Nanasi, R. Palotai, A. Rak, M. S. Szalay-Beko and P. Csermely. Edited by: B. Vedres, M. Scotti (2012) How creative elements help the recovery of networks after crisis: lessons from biology. Cambridge University Press, Networks in Social Policy Problems p. 179-188
- I. A. Kovács and F. Iglói (2011) Renormalization group study of random quantum magnets, J. Phys.: Condens. Matter 23 404204 [arXiv]
- I. A. Kovács and F. Iglói (2011) Infinite-disorder scaling of random quantum magnets in three and higher dimensions Phys. Rev. B 83, 174207 [arXiv]
- I. A. Kovács and F. Iglói (2010) Renormalization group study of the two-dimensional random transverse-field Ising model Phys. Rev. B 82, 054437 [arXiv]
- I. A. Kovács and F. Iglói (2009) Critical behavior and entanglement of the random transverse-field Ising model between one and two dimensions Phys. Rev. B 80, 214416 [arXiv]
- P. Csermely, I. A. Kovács, Á. Mihalik, T. Nánási, R. Palotai, Á. Rák és M. Szalay (2009) Hogyan küzdik le a válságokat a biológiai hálózatok, és mit tanulhatunk el tőlük? Magyar Tudomány 170, 1381-1390 (in hungarian)
- M. Karsai, I. A. Kovács, J-Ch. Angles d’Auriac and F. Iglói (2008) Density of critical clusters in strips of strongly disordered systems Phys. Rev E 78 061109 [arXiv]
- F. Iglói and I. A. Kovács (2008) Griffiths-McCoy singularities in random quantum spin chains: Exact results Phys. Rev. B 77 144203 [arXiv]