{"topic":"many-body-quantum-simulation","sort":"top","limit":25,"offset":0,"count":25,"papers":[{"id":"arxiv:1404.0686","kind":"review","title":"Many body localization and thermalization in quantum statistical mechanics","authors":["Rahul Nandkishore","David A. Huse"],"author_count":2,"year":2014,"published":"2014-04-02","venue":"Annual Review of Condensed Matter Physics, Vol. 6: 15-38 (2015)","cited_by":2493,"doi":"10.1146/annurev-conmatphys-031214-014726","arxiv_id":"1404.0686","nct_id":null,"source_url":"https://arxiv.org/abs/1404.0686","archive_url":"https://space-kitty.com/papers/arxiv:1404.0686","updated":"2014-06-09","pmid":null,"pmcid":null,"openalex_id":"W2137084802","pdf_url":"https://arxiv.org/pdf/1404.0686","abstract":"We review some recent developments in the statistical mechanics of isolated quantum systems. We provide a brief introduction to quantum thermalization, paying particular attention to the `Eigenstate Thermalization Hypothesis' (ETH), and the resulting `single-eigenstate statistical mechanics'. We then focus on a class of systems which fail to quantum thermalize and whose eigenstates violate the ETH: These are the many-body Anderson localized systems; their long-time properties are not captured by the conventional ensembles of quantum statistical mechanics. These systems can locally remember forever information about their local initial conditions, and are thus of interest for possibilities of storing quantum information. We discuss key features of many-body localization (MBL), and review a phenomenology of the MBL phase. Single-eigenstate statistical mechanics within the MBL phase reveals dynamically-stable ordered phases, and phase transitions among them, that are invisible to equilibrium statistical mechanics and can occur at high energy and low spatial dimensionality where equilibrium ordering is forbidden.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["cond-mat.stat-mech","cond-mat.dis-nn","cond-mat.str-el","hep-th"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1804.11065","kind":"article","title":"Many-body localization, thermalization, and entanglement","authors":["Dmitry A. Abanin","Ehud Altman","Immanuel Bloch","Maksym Serbyn"],"author_count":4,"year":2018,"published":"2018-04-30","venue":"Rev. Mod. Phys. 91, 021001 (2019)","cited_by":1828,"doi":"10.1103/revmodphys.91.021001","arxiv_id":"1804.11065","nct_id":null,"source_url":"https://arxiv.org/abs/1804.11065","archive_url":"https://space-kitty.com/papers/arxiv:1804.11065","updated":"2019-02-13","pmid":null,"pmcid":null,"openalex_id":"W2914454605","pdf_url":"https://arxiv.org/pdf/1804.11065","abstract":"Thermalizing quantum systems are conventionally described by statistical mechanics at equilibrium. However, not all systems fall into this category, with many body localization providing a generic mechanism for thermalization to fail in strongly disordered systems. Many-body localized (MBL) systems remain perfect insulators at non-zero temperature, which do not thermalize and therefore cannot be described using statistical mechanics. In this Colloquium we review recent theoretical and experimental advances in studies of MBL systems, focusing on the new perspective provided by entanglement and non-equilibrium experimental probes such as quantum quenches. Theoretically, MBL systems exhibit a new kind of robust integrability: an extensive set of quasi-local integrals of motion emerges, which provides an intuitive explanation of the breakdown of thermalization. A description based on quasi-local integrals of motion is used to predict dynamical properties of MBL systems, such as the spreading of quantum entanglement, the behavior of local observables, and the response to external dissipative processes. Furthermore, MBL systems can exhibit eigenstate transitions and quantum orders forbidden in thermodynamic equilibrium. We outline the current theoretical understanding of the quantum-to-classical transition between many-body localized and ergodic phases, and anomalous transport in the vicinity of that transition. Experimentally, synthetic quantum systems, which are well-isolated from an external thermal reservoir, provide natural platforms for realizing the MBL phase. We review recent experiments with ultracold atoms, trapped ions, superconducting qubits, and quantum materials, in which different signatures of many-body localization have been observed. We conclude by listing outstanding challenges and promising future research directions.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["cond-mat.dis-nn","cond-mat.mes-hall","cond-mat.quant-gas","cond-mat.stat-mech","quant-ph"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1501.05661","kind":"article","title":"Observation of many-body localization of interacting fermions in a quasirandom optical lattice","authors":["Michael Schreiber","Sean S. Hodgman","Pranjal Bordia","Henrik P. Lüschen","Mark H. Fischer","Ronen Vosk","Ehud Altman","Ulrich Schneider","Immanuel Bloch"],"author_count":9,"year":2015,"published":"2015-07-30","venue":"Science","cited_by":1728,"doi":"10.1126/science.aaa7432","arxiv_id":"1501.05661","nct_id":null,"source_url":"https://doi.org/10.1126/science.aaa7432","archive_url":"https://space-kitty.com/papers/arxiv:1501.05661","updated":"2015-01-22","pmid":"26229112","pmcid":null,"openalex_id":"W2104281360","pdf_url":"https://arxiv.org/pdf/1501.05661","abstract":"We experimentally observe many-body localization of interacting fermions in a one-dimensional quasi-random optical lattice. We identify the many-body localization transition through the relaxation dynamics of an initially-prepared charge density wave. For sufficiently weak disorder the time evolution appears ergodic and thermalizing, erasing all remnants of the initial order. In contrast, above a critical disorder strength a significant portion of the initial ordering persists, thereby serving as an effective order parameter for localization. The stationary density wave order and the critical disorder value show a distinctive dependence on the interaction strength, in agreement with numerical simulations. We connect this dependence to the ubiquitous logarithmic growth of entanglement entropy characterizing the generic many-body localized phase.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1010.1992","kind":"article","title":"Many-body localization phase transition","authors":["Arijeet Pal","David A. Huse"],"author_count":2,"year":2010,"published":"2010-11-09","venue":"Physical Review B","cited_by":1499,"doi":"10.1103/physrevb.82.174411","arxiv_id":"1010.1992","nct_id":null,"source_url":"https://doi.org/10.1103/physrevb.82.174411","archive_url":"https://space-kitty.com/papers/arxiv:1010.1992","updated":"2010-10-11","pmid":null,"pmcid":null,"openalex_id":"W1967106943","pdf_url":"https://arxiv.org/pdf/1010.1992","abstract":"We use exact diagonalization to explore the many-body localization transition in a random-field spin-1/2 chain. We examine the correlations within each many-body eigenstate, looking at all high-energy states and thus effectively working at infinite temperature. For weak random field the eigenstates are thermal, as expected in this nonlocalized, \"ergodic\" phase. For strong random field the eigenstates are localized, with only short-range entanglement. We roughly locate the localization transition and examine some of its finite-size scaling, finding that this quantum phase transition at nonzero temperature might be showing infinite-randomness scaling with a dynamic critical exponent $z\\rightarrow\\infty$.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1408.5148","kind":"article","title":"Quantum many-body systems out of equilibrium","authors":["Jens Eisert","M. Friesdorf","Christian Gogolin"],"author_count":3,"year":2015,"published":"2015-02-01","venue":"Nature Physics","cited_by":1255,"doi":"10.1038/nphys3215","arxiv_id":"1408.5148","nct_id":null,"source_url":"https://doi.org/10.1038/nphys3215","archive_url":"https://space-kitty.com/papers/arxiv:1408.5148","updated":"2015-09-01","pmid":null,"pmcid":null,"openalex_id":"W2077599442","pdf_url":"http://hdl.handle.net/2117/26765","abstract":"Closed quantum many-body systems out of equilibrium pose several long-standing problems in physics. Recent years have seen a tremendous progress in approaching these questions, not least due to experiments with cold atoms and trapped ions in instances of quantum simulations. This article provides an overview on the progress in understanding dynamical equilibration and thermalisation of closed quantum many-body systems out of equilibrium due to quenches, ramps and periodic driving. It also addresses topics such as the eigenstate thermalisation hypothesis, typicality, transport, many-body localisation, universality near phase transitions, and prospects for quantum simulations.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"other-oa","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1509.01160","kind":"article","title":"Measuring entanglement entropy in a quantum many-body system","authors":["Rajibul Islam","Ruichao Ma","Philipp M. Preiss","M. Eric Tai","Alexander Lukin","Matthew Rispoli","Markus Greiner"],"author_count":7,"year":2015,"published":"2015-12-01","venue":"Nature","cited_by":1168,"doi":"10.1038/nature15750","arxiv_id":"1509.01160","nct_id":null,"source_url":"https://doi.org/10.1038/nature15750","archive_url":"https://space-kitty.com/papers/arxiv:1509.01160","updated":"2015-09-03","pmid":"26632587","pmcid":null,"openalex_id":"W2183109806","pdf_url":"https://arxiv.org/pdf/1509.01160","abstract":"Entanglement is one of the most intriguing features of quantum mechanics. It describes non-local correlations between quantum objects, and is at the heart of quantum information sciences. Entanglement is rapidly gaining prominence in diverse fields ranging from condensed matter to quantum gravity. Despite this generality, measuring entanglement remains challenging. This is especially true in systems of interacting delocalized particles, for which a direct experimental measurement of spatial entanglement has been elusive. Here, we measure entanglement in such a system of itinerant particles using quantum interference of many-body twins. Leveraging our single-site resolved control of ultra-cold bosonic atoms in optical lattices, we prepare and interfere two identical copies of a many-body state. This enables us to directly measure quantum purity, Renyi entanglement entropy, and mutual information. These experiments pave the way for using entanglement to characterize quantum phases and dynamics of strongly-correlated many-body systems.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1609.08684","kind":"article","title":"Observation of a discrete time crystal","authors":["J. Zhang","Paul Hess","A. Kyprianidis","Patrick Becker","A. Lee","J. Smith","Guido Pagano","Ionut-Dragos Potirniche","Andrew C. Potter","Ashvin Vishwanath","Norman Y. Yao","Christopher R. Monroe"],"author_count":12,"year":2017,"published":"2017-03-07","venue":"Nature","cited_by":1142,"doi":"10.1038/nature21413","arxiv_id":"1609.08684","nct_id":null,"source_url":"https://doi.org/10.1038/nature21413","archive_url":"https://space-kitty.com/papers/arxiv:1609.08684","updated":"2016-09-27","pmid":"28277505","pmcid":null,"openalex_id":"W2526468162","pdf_url":"https://arxiv.org/pdf/1609.08684","abstract":"Spontaneous symmetry breaking is a fundamental concept in many areas of physics, ranging from cosmology and particle physics to condensed matter. A prime example is the breaking of spatial translation symmetry, which underlies the formation of crystals and the phase transition from liquid to solid. Analogous to crystals in space, the breaking of translation symmetry in time and the emergence of a \"time crystal\" was recently proposed, but later shown to be forbidden in thermal equilibrium. However, non-equilibrium Floquet systems subject to a periodic drive can exhibit persistent time-correlations at an emergent sub-harmonic frequency. This new phase of matter has been dubbed a \"discrete time crystal\" (DTC). Here, we present the first experimental observation of a discrete time crystal, in an interacting spin chain of trapped atomic ions. We apply a periodic Hamiltonian to the system under many-body localization (MBL) conditions, and observe a sub-harmonic temporal response that is robust to external perturbations. Such a time crystal opens the door for studying systems with long-range spatial-temporal correlations and novel phases of matter that emerge under intrinsically non-equilibrium conditions.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1202.5532","kind":"article","title":"Unbounded Growth of Entanglement in Models of Many-Body Localization","authors":["Jens Hjorleifur Bardarson","Frank Pollmann","Joel E. Moore"],"author_count":3,"year":2012,"published":"2012-07-03","venue":"Physical Review Letters","cited_by":1057,"doi":"10.1103/physrevlett.109.017202","arxiv_id":"1202.5532","nct_id":null,"source_url":"https://doi.org/10.1103/physrevlett.109.017202","archive_url":"https://space-kitty.com/papers/arxiv:1202.5532","updated":"2012-07-10","pmid":"23031128","pmcid":null,"openalex_id":"W2036346714","pdf_url":"https://arxiv.org/pdf/1202.5532","abstract":"An important and incompletely answered question is whether a closed quantum system of many interacting particles can be localized by disorder. The time evolution of simple (unentangled) initial states is studied numerically for a system of interacting spinless fermions in one dimension described by the random-field XXZ Hamiltonian. Interactions induce a dramatic change in the propagation of entanglement and a smaller change in the propagation of particles. For even weak interactions, when the system is thought to be in a many-body localized phase, entanglement shows neither localized nor diffusive behavior but grows without limit in an infinite system: interactions act as a singular perturbation on the localized state with no interactions. The significance for proposed atomic experiments is that local measurements will show a large but nonthermal entropy in the many-body localized state. This entropy develops slowly (approximately logarithmically) over a diverging time scale as in glassy systems.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1411.0660","kind":"article","title":"Many-body localization edge in the random-field Heisenberg chain","authors":["David J. Luitz","Nicolas Laflorencie","Fabien Alet"],"author_count":3,"year":2015,"published":"2015-02-09","venue":"Physical Review B","cited_by":1026,"doi":"10.1103/physrevb.91.081103","arxiv_id":"1411.0660","nct_id":null,"source_url":"https://doi.org/10.1103/physrevb.91.081103","archive_url":"https://space-kitty.com/papers/arxiv:1411.0660","updated":"2014-12-23","pmid":null,"pmcid":null,"openalex_id":"W2127488783","pdf_url":"https://arxiv.org/pdf/1411.0660","abstract":"We present a large scale exact diagonalization study of the one dimensional spin $1/2$ Heisenberg model in a random magnetic field. In order to access properties at varying energy densities across the entire spectrum for system sizes up to $L=22$ spins, we use a spectral transformation which can be applied in a massively parallel fashion. Our results allow for an energy-resolved interpretation of the many body localization transition including the existence of an extensive many-body mobility edge. The ergodic phase is well characterized by Gaussian orthogonal ensemble statistics, volume-law entanglement, and a full delocalization in the Hilbert space. Conversely, the localized regime displays Poisson statistics, area-law entanglement and non ergodicity in the Hilbert space where a true localization never occurs. We perform finite size scaling to extract the critical edge and exponent of the localization length divergence.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1711.03528","kind":"article","title":"Weak ergodicity breaking from quantum many-body scars","authors":["Christopher J. Turner","Alexios A. Michailidis","Dmitry A. Abanin","Maksym Serbyn","Zlatko Papić"],"author_count":5,"year":2018,"published":"2018-05-10","venue":"Nature Physics","cited_by":995,"doi":"10.1038/s41567-018-0137-5","arxiv_id":"1711.03528","nct_id":null,"source_url":"https://doi.org/10.1038/s41567-018-0137-5","archive_url":"https://space-kitty.com/papers/arxiv:1711.03528","updated":"2017-11-15","pmid":null,"pmcid":null,"openalex_id":"W3099451552","pdf_url":"https://arxiv.org/pdf/1711.03528","abstract":"Certain wave functions of non-interacting quantum chaotic systems can exhibit \"scars\" in the fabric of their real-space density profile. Quantum scarred wave functions concentrate in the vicinity of unstable periodic classical trajectories. We introduce the notion of many-body quantum scars which reflect the existence of a subset of special many-body eigenstates concentrated in certain parts of the Hilbert space. We demonstrate the existence of scars in the Fibonacci chain -- the one- dimensional model with a constrained local Hilbert space realized in the 51 Rydberg atom quantum simulator [H. Bernien et al., arXiv:1707.04344]. The quantum scarred eigenstates are embedded throughout the thermalizing many-body spectrum, but surprisingly lead to direct experimental signatures such as robust oscillations following a quench from a charge-density wave state found in experiment. We develop a model based on a single particle hopping on the Hilbert space graph, which quantitatively captures the scarred wave functions up to large systems of L = 32 atoms. Our results suggest that scarred many-body bands give rise to a new universality class of quantum dynamics, which opens up opportunities for creating and manipulating novel states with long-lived coherence in systems that are now amenable to experimental study.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1604.04178","kind":"article","title":"Exploring the many-body localization transition in two dimensions","authors":["Jae-yoon Choi","Sebastian J. Hild","Johannes Zeiher","Peter Schauß","Antonio Rubio-Abadal","Tarik Yefsah","Vedika Khemani","David A. Huse","Immanuel Bloch","Christian Groß"],"author_count":10,"year":2016,"published":"2016-06-24","venue":"Science","cited_by":979,"doi":"10.1126/science.aaf8834","arxiv_id":"1604.04178","nct_id":null,"source_url":"https://doi.org/10.1126/science.aaf8834","archive_url":"https://space-kitty.com/papers/arxiv:1604.04178","updated":"2016-04-14","pmid":"27339981","pmcid":null,"openalex_id":"W2336937015","pdf_url":"https://arxiv.org/pdf/1604.04178","abstract":"One fundamental assumption in statistical physics is that generic closed quantum many-body systems thermalize under their own dynamics. Recently, the emergence of many-body localized systems has questioned this concept, challenging our understanding of the connection between statistical physics and quantum mechanics. Here we report on the observation of a many-body localization transition between thermal and localized phases for bosons in a two-dimensional disordered optical lattice. With our single site resolved measurements we track the relaxation dynamics of an initially prepared out-of-equilibrium density pattern and find strong evidence for a diverging length scale when approaching the localization transition. Our experiments mark the first demonstration and in-depth characterization of many-body localization in a regime not accessible with state-of-the-art simulations on classical computers.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1603.08001","kind":"article","title":"Floquet Time Crystals","authors":["Dominic V. Else","Bela Bauer","Chetan Nayak"],"author_count":3,"year":2016,"published":"2016-08-25","venue":"Physical Review Letters","cited_by":973,"doi":"10.1103/physrevlett.117.090402","arxiv_id":"1603.08001","nct_id":null,"source_url":"https://doi.org/10.1103/physrevlett.117.090402","archive_url":"https://space-kitty.com/papers/arxiv:1603.08001","updated":"2016-06-08","pmid":"27610834","pmcid":null,"openalex_id":"W2314480200","pdf_url":"https://arxiv.org/pdf/1603.08001","abstract":"We define what it means for time translation symmetry to be spontaneously broken in a quantum system, and show with analytical arguments and numerical simulations that this occurs in a large class of many-body-localized driven systems with discrete time-translation symmetry.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum many-body systems"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2011.09486","kind":"article","title":"Quantum Many-Body Scars and Weak Breaking of Ergodicity","authors":["Maksym Serbyn","Dmitry A. Abanin","Zlatko Papić"],"author_count":3,"year":2020,"published":"2020-11-18","venue":"Nat. Phys. (2021)","cited_by":541,"doi":"10.1038/s41567-021-01230-2","arxiv_id":"2011.09486","nct_id":null,"source_url":"https://arxiv.org/abs/2011.09486","archive_url":"https://space-kitty.com/papers/arxiv:2011.09486","updated":"2020-11-18","pmid":null,"pmcid":null,"openalex_id":"W3102594775","pdf_url":"https://arxiv.org/pdf/2011.09486","abstract":"Recent discovery of persistent revivals in quantum simulators based on Rydberg atoms have pointed to the existence of a new type of dynamical behavior that challenged the conventional paradigms of integrability and thermalization. This novel collective effect has been named quantum many-body scars by analogy with weak ergodicity breaking of a single particle inside a stadium billiard. In this overview, we provide a pedagogical introduction to quantum many-body scars and highlight the newly emerged connections with the semiclassical quantization of many-body systems. We discuss the relation between scars and more general routes towards weak violations of ergodicity due to \"embedded\" algebras and non-thermal eigenstates, and highlight possible applications of scars in quantum technology.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["quant-ph","cond-mat.quant-gas","cond-mat.stat-mech","cond-mat.str-el","nlin.CD"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1204.5789","kind":"article","title":"Engineered two-dimensional Ising interactions in a trapped-ion quantum simulator with hundreds of spins","authors":["J. Britton","Brian C. Sawyer","Adam C. Keith","C.‐C. Joseph Wang","James K. Freericks","Hermann Uys","Michael J. Biercuk","J. J. Bollinger"],"author_count":8,"year":2012,"published":"2012-04-01","venue":"Nature","cited_by":941,"doi":"10.1038/nature10981","arxiv_id":"1204.5789","nct_id":null,"source_url":"https://doi.org/10.1038/nature10981","archive_url":"https://space-kitty.com/papers/arxiv:1204.5789","updated":"2012-04-25","pmid":"22538611","pmcid":null,"openalex_id":"W2006051991","pdf_url":"https://arxiv.org/pdf/1204.5789","abstract":"The presence of long-range quantum spin correlations underlies a variety of physical phenomena in condensed matter systems, potentially including high-temperature superconductivity. However, many properties of exotic strongly correlated spin systems (e.g., spin liquids) have proved difficult to study, in part because calculations involving N-body entanglement become intractable for as few as N~30 particles. Feynman divined that a quantum simulator - a special-purpose \"analog\" processor built using quantum particles (qubits) - would be inherently adept at such problems. In the context of quantum magnetism, a number of experiments have demonstrated the feasibility of this approach. However, simulations of quantum magnetism allowing controlled, tunable interactions between spins localized on 2D and 3D lattices of more than a few 10's of qubits have yet to be demonstrated, owing in part to the technical challenge of realizing large-scale qubit arrays. Here we demonstrate a variable-range Ising-type spin-spin interaction J_ij on a naturally occurring 2D triangular crystal lattice of hundreds of spin-1/2 particles (9Be+ ions stored in a Penning trap), a computationally relevant scale more than an order of magnitude larger than existing experiments. We show that a spin-dependent optical dipole force can produce an antiferromagnetic interaction J_ij ~ 1/d_ij^a, where a is tunable over 0