- Open Access
Quantum Criticality Under Decoherence or Weak Measurement
PRX Quantum 4, 030317 – Published 4 August, 2023
DOI: https://doi.org/10.1103/PRXQuantum.4.030317
Abstract
Decoherence inevitably happens when a quantum state is exposed to its environment, which can affect quantum critical points (QCPs) in a nontrivial way. As was pointed out in the recent literature on conformal field theory (CFT) [Garratt et al. Measurements conspire nonlocally to restructure critical quantum states, arXiv:2207.09476 (2022)], the effect of weak measurement can be mathematically mapped to the problem of boundary CFT. In this work, we focus on the QCPs, whose boundary and defect effects have attracted enormous theoretical and numerical interests very recently. We focus on decoherence caused by weak measurements with and without postselecting the measurement outcomes. Our main results are as follows: (1) for an Wilson-Fisher QCP under weak measurement with postselection, an observer would, in general, observe two different types of boundary and defect criticality with very different behaviors from the well-known Wilson-Fisher fixed points; in particular, it is possible to observe the recently proposed exotic “extraordinary-log” correlation. (2) An extra quantum phase transition can be driven by decoherence, if we consider quantities nonlinear with the decohered density matrix, such as the Renyi entropy. We demonstrate the connection between this transition to the information-theoretic transition driven by an error in the toric code model. (3) When there is no postselection, though correlation functions between local operators remain the same as the undecohered pure state, nonlocal operators such as the “disorder operator” would have qualitatively distinct behaviors; and we also show that the decoherence can lead to confinement.
Physics Subject Headings (PhySH)
Popular Summary
Quantum decoherence serves as the link between the microscopic quantum realm and the macroscopic classical realm. This process involves the gradual loss of quantum information in a quantum system as it becomes entangled with environmental degrees of freedom. Decoherence can also be understood as the system being effectively ”measured” by the environment in a certain way. Understanding the behavior of quantum systems, particularly quantum many-body systems, under the influence of decoherence is of significant importance and interest. Quantum critical states represent one big class of archetypal quantum many-body systems, and in this work, we investigate the effect of decoherence and measurement on systems at quantum critical points.
By employing the powerful techniques of field theory and the renormalization group, we demonstrate that decoherence and measurements can steer a conventional quantum critical state to display unusual and unexpected scaling behaviors. In some cases, they can even induce novel phase transitions. Remarkably, an unconventional quantum critical point featuring fractionalization may experience “confinement” as a consequence of decoherence. Furthermore, our investigation reveals that decoherence can drive topological phase transitions for specific types of topological order. This implies that the quantum information encoded within the topological order becomes irretrievably lost once a critical level of entanglement with the environment is surpassed.
Article Text
References (97)
- W. H. Zurek, Decoherence, einselection, and the quantum origins of the classical, Rev. Mod. Phys. 75, 715 (2003).
- J. Preskill, Quantum Computing in the NISQ era and beyond, Quantum 2, 79 (2018).
- C. Song, D. Xu, P. Zhang, J. Wang, Q. Guo, W. Liu, K. Xu, H. Deng, K. Huang, D. Zheng, S.-B. Zheng, H. Wang, X. Zhu, C.-Y. Lu, and J.-W. Pan, Demonstration of Topological Robustness of Anyonic Braiding Statistics with a Superconducting Quantum Circuit, Phys. Rev. Lett. 121, 030502 (2018).
- K. J. Satzinger, et al., Realizing topologically ordered states on a quantum processor, Science 374, 1237 (2021).
- S. de Léséleuc, V. Lienhard, P. Scholl, D. Barredo, S. Weber, N. Lang, H. P. Büchler, T. Lahaye, and A. Browaeys, Observation of a symmetry-protected topological phase of interacting bosons with Rydberg atoms, Science 365, 775 (2019).
- A. Keesling, A. Omran, H. Levine, H. Bernien, H. Pichler, S. Choi, R. Samajdar, S. Schwartz, P. Silvi, S. Sachdev, P. Zoller, M. Endres, M. Greiner, V. Vuletić, and M. D. Lukin, Quantum Kibble–Zurek mechanism and critical dynamics on a programmable Rydberg simulator, Nature 568, 207 (2019).
- G. Semeghini, H. Levine, A. Keesling, S. Ebadi, T. T. Wang, D. Bluvstein, R. Verresen, H. Pichler, M. Kalinowski, R. Samajdar, A. Omran, S. Sachdev, A. Vishwanath, M. Greiner, V. Vuletić, and M. D. Lukin, Probing topological spin liquids on a programmable quantum simulator, Science 374, 1242 (2021).
- J. Y. Lee, W. Ji, Z. Bi, and M. P. A. Fisher, Decoding measurement-prepared quantum phases and transitions: From Ising model to gauge theory, and beyond, ArXiv:2208.11699 (2022).
- G.-Y. Zhu, N. Tantivasadakarn, A. Vishwanath, S. Trebst, and R. Verresen, Nishimori’s cat: Stable long-range entanglement from finite-depth unitaries and weak measurements, ArXiv:2208.11136 (2022).
- C. de Groot, A. Turzillo, and N. Schuch, Symmetry protected topological order in open quantum systems, Quantum 6, 856 (2022).
- J. Y. Lee, Y.-Z. You, and C. Xu, Symmetry protected topological phases under decoherence, ArXiv:2210.16323 (2022).
- R. Ma and C. Wang, Average symmetry-protected topological phases, ArXiv:2209.02723 (2022).
- J.-H. Zhang, Y. Qi, and Z. Bi, Strange correlation function for average symmetry-protected topological phases, ArXiv:2210.17485 (2022).
- S. J. Garratt, Z. Weinstein, and E. Altman, Measurements conspire nonlocally to restructure critical quantum states, ArXiv:2207.09476 (2022).
- C. L. Kane and M. P. A. Fisher, Transmission through barriers and resonant tunneling in an interacting one-dimensional electron gas, Phys. Rev. B 46, 15233 (1992).
- C. Xu and T. Senthil, Wave functions of bosonic symmetry protected topological phases, Phys. Rev. B 87, 174412 (2013).
- Y.-Z. You, Z. Bi, A. Rasmussen, K. Slagle, and C. Xu, Wave Function and Strange Correlator of Short-Range Entangled States, Phys. Rev. Lett. 112, 247202 (2014).
- T. Grover and A. Vishwanath, Quantum criticality in topological insulators and superconductors: Emergence of strongly coupled Majoranas and Supersymmetry, ArXiv:1206.1332 (2012).
- L. Zhang and F. Wang, Unconventional Surface Critical Behavior Induced by a Quantum Phase Transition From the Two-Dimensional Affleck-Kennedy-Lieb-Tasaki Phase to a Néel-Ordered Phase, Phys. Rev. Lett. 118, 087201 (2017).
- C. Ding, L. Zhang, and W. Guo, Engineering Surface Critical Behavior of ()-Dimensional O(3) Quantum Critical Points, Phys. Rev. Lett. 120, 235701 (2018).
- L. Weber, F. Parisen Toldin, and S. Wessel, Nonordinary edge criticality of two-dimensional quantum critical magnets, Phys. Rev. B 98, 140403 (2018).
- L. Weber and S. Wessel, Nonordinary criticality at the edges of planar spin-1 Heisenberg antiferromagnets, Phys. Rev. B 100, 054437 (2019).
- Y. Xu, X.-C. Wu, C.-M. Jian, and C. Xu, Topological edge and interface states at bulk disorder-to-order quantum critical points, Phys. Rev. B 101, 184419 (2020).
- C.-M. Jian, Y. Xu, X.-C. Wu, and C. Xu, Continuous Néel-VBS quantum phase transition in non-local one-dimensional systems with SO(3) symmetry, SciPost Phys. 10, 33 (2021).
- M. A. Metlitski, Boundary criticality of the model in critically revisited, SciPost Phys. 12, 131 (2022).
- J. Padayasi, A. Krishnan, M. A. Metlitski, I. A. Gruzberg, and M. Meineri, The extraordinary boundary transition in the model via conformal bootstrap, SciPost Phys. 12, 190 (2022).
- S. Liu, H. Shapourian, A. Vishwanath, and M. A. Metlitski, Magnetic impurities at quantum critical points: Large- expansion and connections to symmetry-protected topological states, Phys. Rev. B 104, 104201 (2021).
- F. Parisen Toldin, Boundary Critical Behavior of the Three-Dimensional Heisenberg Universality Class, Phys. Rev. Lett. 126, 135701 (2021).
- F. Parisen Toldin and M. A. Metlitski, Boundary Criticality of the Model: From Normal to Extraordinary, Phys. Rev. Lett. 128, 215701 (2022).
- R. Ma, L. Zou, and C. Wang, Edge physics at the deconfined transition between a quantum spin Hall insulator and a superconductor, SciPost Phys. 12, 196 (2022).
- E. Dennis, A. Kitaev, A. Landahl, and J. Preskill, Topological quantum memory, J. Math. Phys. 43, 4452 (2002).
- E. Ardonne, P. Fendley, and E. Fradkin, Topological order and conformal quantum critical points, Ann. Phys. (N. Y.) 310, 493 (2004).
- A. Jamiołkowski, Linear transformations which preserve trace and positive semidefiniteness of operators, Rep. Math. Phys. 3, 275 (1972).
- M.-D. Choi, Completely positive linear maps on complex matrices, Linear Algebra Appl. 10, 285 (1975).
- Note that , where if then . Accordingly, the correlation function only acquires a local correction.
- A. Krishnan and M. A. Metlitski, A plane defect in the model, ArXiv:2301.05728 (2023).
- Formally, we can evaluate the Renyi entropy, and take the limit to obtain the behavior of the von Neumann entropy.
- K. Ohno and Y. Okabe, The Expansion for the -vector model in the semi-infinite space, Prog. Theor. Phys. 70, 1226 (1983).
- C. L. Henley, Ordering Due to Disorder in a Frustrated Vector Antiferromagnet, Phys. Rev. Lett. 62, 2056 (1989).
- P. Chandra, P. Coleman, and A. I. Larkin, Ising Transition in Frustrated Heisenberg Models, Phys. Rev. Lett. 64, 88 (1990).
- Q. Si and E. Abrahams, Strong Correlations and Magnetic Frustration in the High Iron Pnictides, Phys. Rev. Lett. 101, 076401 (2008).
- C. Fang, H. Yao, W.-F. Tsai, J. Hu, and S. A. Kivelson, Theory of electron nematic order in Lafeaso, Phys. Rev. B 77, 224509 (2008).
- C. Xu, M. Müller, and S. Sachdev, Ising and spin orders in the iron-based superconductors, Phys. Rev. B 78, 020501 (2008).
- H. Jeffreys, Theory of Probability (The Clarendon Press, Oxford, 1948), 2nd ed.
- J. J. Meyer, Fisher information in noisy intermediate-scale quantum applications, Quantum 5, 539 (2021).
- Y. Bao, S. Choi, and E. Altman, Theory of the phase transition in random unitary circuits with measurements, Phys. Rev. B 101, 104301 (2020).
- However, it does not monotonically decrease under quantum channels anymore.
- N. Friis, D. Orsucci, M. Skotiniotis, P. Sekatski, V. Dunjko, H. J. Briegel, and W. Dür, Flexible resources for quantum metrology, New J. Phys. 19, 063044 (2017).
- H. Nishimori, Internal energy, specific heat and correlation function of the bond-random Ising model, Prog. Theor. Phys. 66, 1169 (1981).
- H. Nishimori, Geometry-induced phase transition in the Ising model, J. Phys. Soc. Jpn. 55, 3305 (1986).
- P. Le Doussal and A. B. Harris, Location of the Ising Spin-Glass Multicritical Point on Nishimori’s Line, Phys. Rev. Lett. 61, 625 (1988).
- The conclusion here should generally hold for the decoherence channel and correlation functions of local operators, i.e., as long as (i) the local operator is the primary field with the lowest scaling dimension of a certain representation of the symmetry, and (ii) the decoherence channel explicitly preserves this symmetry (with a “doubled” symmetry condition) and commute with the local operator except for the close vicinity of the operator, then the decoherence should not change the long-distance scaling of the correlation function.
- L. P. Kadanoff and H. Ceva, Determination of an operator algebra for the two-dimensional Ising model, Phys. Rev. B 3, 3918 (1971).
- W. Ji and X.-G. Wen, Categorical symmetry and noninvertible anomaly in symmetry-breaking and topological phase transitions, Phys. Rev. Res. 2, 033417 (2020).
- X.-C. Wu, W. Ji, and C. Xu, Categorical symmetries at criticality, J. Stat. Mech.: Theory Exp. 2021, 073101 (2021).
- J. Zhao, Z. Yan, M. Cheng, and Z. Y. Meng, Higher-form symmetry breaking at Ising transitions, Phys. Rev. Res. 3, 033024 (2021).
- X.-C. Wu, C.-M. Jian, and C. Xu, Universal features of higher-form symmetries at phase transitions, SciPost Phys. 11, 033 (2021).
- Y.-C. Wang, N. Ma, M. Cheng, and Z. Y. Meng, Scaling of the disorder operator at deconfined quantum criticality, SciPost Phys. 13, 123 (2022).
- W. Jiang, B.-B. Chen, Z. H. Liu, J. Rong, F. F. Assaad, M. Cheng, K. Sun, and Z. Y. Meng, Fermion disorder operator: The hedgehog and the fox of quantum many-body entanglement, ArXiv:2209.07103 (2022).
- Z. H. Liu, W. Jiang, B.-B. Chen, J. Rong, M. Cheng, K. Sun, Z. Y. Meng, and F. F. Assaad, Fermion disorder operator at Gross-Neveu and deconfined quantum criticalities, ArXiv:2212.11821 (2022).
- It was also called by other names, such as patch operator [54], and order diagnosis operator [55, 57], etc.
- M. E. Peskin, Mandelstam-’t hooft duality in abelian lattice models, Ann. Phys. (N. Y.) 113, 122 (1978).
- C. Dasgupta and B. I. Halperin, Phase Transition in a Lattice Model of Superconductivity, Phys. Rev. Lett. 47, 1556 (1981).
- M. P. A. Fisher and D. H. Lee, Correspondence between two-dimensional bosons and a bulk superconductor in a magnetic field, Phys. Rev. B 39, 2756 (1989).
- B. Estienne, J.-M. Stéphan, and W. Witczak-Krempa, Cornering the universal shape of fluctuations, Nat. Commun. 13, 287 (2022).
- A. Klauser, J. Mossel, J.-S. Caux, and J. van den Brink, Spin-Exchange Dynamical Structure Factor of the Heisenberg Chain, Phys. Rev. Lett. 106, 157205 (2011).
- M. Punk, D. Chowdhury, and S. Sachdev, Topological excitations and the dynamic structure factor of spin liquids on the kagome lattice, Nat. Phys. 10, 289 (2014).
- W. Zhu, S. shu Gong, and D. N. Sheng, Identifying spinon excitations from dynamic structure factor of spin-1/2 Heisenberg antiferromagnet on the kagome lattice, Proc. Natl. Acad. Sci. 116, 5437 (2019).
- S. Sachdev, Quantum Phase Transitions (Cambridge University Press, Cambridge, 2011). 2nd ed.
- M. P. A. Fisher, P. B. Weichman, G. Grinstein, and D. S. Fisher, Boson localization and the superfluid-insulator transition, Phys. Rev. B 40, 546 (1989).
- T. Senthil, A. Vishwanath, L. Balents, S. Sachdev, and M. P. A. Fisher, Deconfined quantum critical points, Science 303, 1490 (2004).
- T. Senthil, L. Balents, S. Sachdev, A. Vishwanath, and M. P. A. Fisher, Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm, Phys. Rev. B 70, 144407 (2004).
- C. Wang, A. Nahum, M. A. Metlitski, C. Xu, and T. Senthil, Deconfined Quantum Critical Points: Symmetries and Dualities, Phys. Rev. X 7, 031051 (2017).
- X.-G. Wen and Y.-S. Wu, Transitions Between the Quantum hall States and Insulators Induced by Periodic Potentials, Phys. Rev. Lett. 70, 1501 (1993).
- K. Wierschem and P. Sengupta, Quenching the Haldane Gap in Spin-1 Heisenberg Antiferromagnets, Phys. Rev. Lett. 112, 247203 (2014).
- K. Wierschem and P. Sengupta, Strange correlations in spin-1 Heisenberg antiferromagnets, Phys. Rev. B 90, 115157 (2014).
- K. Wierschem and P. Sengupta, Characterizing the Haldane phase in quasi-one-dimensional spin-1 Heisenberg antiferromagnets, Mod. Phys. Lett. B 28, 1430017 (2014).
- Z. Ringel and S. H. Simon, Hidden order and flux attachment in symmetry-protected topological phases: A Laughlin-like approach, Phys. Rev. B 91, 195117 (2015).
- H.-Q. Wu, Y.-Y. He, Y.-Z. You, C. Xu, Z. Y. Meng, and Z.-Y. Lu, Quantum Monte Carlo study of strange correlator in interacting topological insulators, Phys. Rev. B 92, 165123 (2015).
- T. Scaffidi and Z. Ringel, Wave functions of symmetry-protected topological phases from conformal field theories, Phys. Rev. B 93, 115105 (2016).
- Y.-Y. He, H.-Q. Wu, Y.-Z. You, C. Xu, Z. Y. Meng, and Z.-Y. Lu, Bona fide interaction-driven topological phase transition in correlated symmetry-protected topological states, Phys. Rev. B 93, 115150 (2016).
- C.-Y. Huang and T.-C. Wei, Detecting and identifying two-dimensional symmetry-protected topological, symmetry-breaking, and intrinsic topological phases with modular matrices via tensor-network methods, Phys. Rev. B 93, 155163 (2016).
- Y.-Y. He, H.-Q. Wu, Z. Y. Meng, and Z.-Y. Lu, Topological invariants for interacting topological insulators. II. Breakdown of single-particle Green’s function formalism, Phys. Rev. B 93, 195164 (2016).
- K. Wierschem and K. S. D. Beach, Detection of symmetry-protected topological order in AKLT states by exact evaluation of the strange correlator, Phys. Rev. B 93, 245141 (2016).
- Y. Zhong, Y. Liu, and H.-G. Luo, Topological phase in 1d topological Kondo insulator: Z2 topological insulator, Haldane-like phase and Kondo breakdown, Eur. Phys. J. B 90, 147 (2017).
- T. Scaffidi, D. E. Parker, and R. Vasseur, Gapless symmetry-protected topological order, Phys. Rev. X 7, 041048 (2017).
- D. J. Williamson, N. Bultinck, and F. Verstraete, Symmetry-enriched topological order in tensor networks: Defects, gauging and anyon condensation, ArXiv:1711.07982 (2017).
- R. Vanhove, M. Bal, D. J. Williamson, N. Bultinck, J. Haegeman, and F. Verstraete, Mapping Topological to Conformal Field Theories Through Strange Correlators, Phys. Rev. Lett. 121, 177203 (2018).
- N. Bultinck, R. Vanhove, J. Haegeman, and F. Verstraete, Global Anomaly Detection in Two-Dimensional Symmetry-Protected Topological Phases, Phys. Rev. Lett. 120, 156601 (2018).
- L. Lootens, R. Vanhove, and F. Verstraete, Cardy states, defect lines and chiral operators of coset CFTs on the lattice, ArXiv:1907.02520 (2019).
- L. Lootens, R. Vanhove, J. Haegeman, and F. Verstraete, Galois Conjugated Tensor Fusion Categories and Nonunitary Conformal Field Theory, Phys. Rev. Lett. 124, 120601 (2020).
- T. D. Ellison, K. Kato, Z.-W. Liu, and T. H. Hsieh, Symmetry-protected sign problem and magic in quantum phases of matter, Quantum 5, 612 (2021).
- R. Fan, S. Vijay, A. Vishwanath, and Y.-Z. You, Self-organized error correction in random unitary circuits with measurement, Phys. Rev. B 103, 174309 (2021).
- T.-C. Lu and S. Vijay, Characterizing long-range entanglement in a mixed state through an emergent order on the entangling surface, ArXiv:2201.07792 (2022).
- C. Zhou, M.-Y. Li, Z. Yan, P. Ye, and Z. Y. Meng, Detecting subsystem symmetry protected topological order through strange correlators, ArXiv:2209.12917 (2022).
- Y. Bao, R. Fan, A. Vishwanath, and E. Altman, Mixed-state topological order and the errorfield double formulation of decoherence-induced transitions, ArXiv:2301.05687 (2023).
- R. Fan, Y. Bao, E. Altman, and A. Vishwanath, Diagnostics of mixed-state topological order and breakdown of quantum memory, ArXiv:2301.05689 (2023).
