1
|
Wang B, Aidelsburger M, Dalibard J, Eckardt A, Goldman N. Cold-Atom Elevator: From Edge-State Injection to the Preparation of Fractional Chern Insulators. Phys Rev Lett 2024; 132:163402. [PMID: 38701474 DOI: 10.1103/physrevlett.132.163402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 03/12/2024] [Indexed: 05/05/2024]
Abstract
Optical box traps offer new possibilities for quantum-gas experiments. Building on their exquisite spatial and temporal control, we propose to engineer system-reservoir configurations using box traps, in view of preparing and manipulating topological atomic states in optical lattices. First, we consider the injection of particles from the reservoir to the system: this scenario is shown to be particularly well suited to activating energy-selective chiral edge currents, but also to prepare fractional Chern insulating ground states. Then, we devise a practical evaporative-cooling scheme to effectively cool down atomic gases into topological ground states. Our open-system approach to optical-lattice settings provides a new path for the investigation of ultracold quantum matter, including strongly correlated and topological phases.
Collapse
Affiliation(s)
- Botao Wang
- CENOLI, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Monika Aidelsburger
- Faculty of Physics, Ludwig-Maximilians-Universität München, Schellingstr. 4, D-80799 Munich, Germany
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 Munich, Germany
| | - Jean Dalibard
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-Université PSL, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - André Eckardt
- Technische Universität Berlin, Institut für Theoretische Physik, Hardenbergstrasse 36, 10623 Berlin, Germany
| | - Nathan Goldman
- CENOLI, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-Université PSL, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| |
Collapse
|
2
|
Coen S, Garbin B, Xu G, Quinn L, Goldman N, Oppo GL, Erkintalo M, Murdoch SG, Fatome J. Nonlinear topological symmetry protection in a dissipative system. Nat Commun 2024; 15:1398. [PMID: 38360729 PMCID: PMC10869785 DOI: 10.1038/s41467-023-44640-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 12/21/2023] [Indexed: 02/17/2024] Open
Abstract
We investigate experimentally and theoretically a system ruled by an intricate interplay between topology, nonlinearity, and spontaneous symmetry breaking. The experiment is based on a two-mode coherently-driven optical resonator where photons interact through the Kerr nonlinearity. In presence of a phase defect, the modal structure acquires a synthetic Möbius topology enabling the realization of spontaneous symmetry breaking in inherently bias-free conditions without fine tuning of parameters. Rigorous statistical tests confirm the robustness of the underlying symmetry protection, which manifests itself by a periodic alternation of the modes reminiscent of period-doubling. This dynamic also confers long term stability to various localized structures including domain walls, solitons, and breathers. Our findings are supported by an effective Hamiltonian model and have relevance to other systems of interacting bosons and to the Floquet engineering of quantum matter. They could also be beneficial to the implementation of coherent Ising machines.
Collapse
Affiliation(s)
- Stéphane Coen
- Physics Department, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand.
| | - Bruno Garbin
- Physics Department, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand
- NcodiN SAS, 10 Boulevard Thomas Gobert, F-91120, Palaiseau, France
| | - Gang Xu
- Physics Department, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, China
| | - Liam Quinn
- Physics Department, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, B-1050, Brussels, Belgium
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-Université PSL, Sorbonne Université, 11 Place Marcelin Berthelot, 75005, Paris, France
| | - Gian-Luca Oppo
- SUPA and Department of Physics, University of Strathclyde, Glasgow, G4 0NG, Scotland
| | - Miro Erkintalo
- Physics Department, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand
| | - Stuart G Murdoch
- Physics Department, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand
| | - Julien Fatome
- Physics Department, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand
- Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, F-21078, Dijon, France
| |
Collapse
|
3
|
Peralta Gavensky L, Sachdev S, Goldman N. Connecting the Many-Body Chern Number to Luttinger's Theorem through Středa's Formula. Phys Rev Lett 2023; 131:236601. [PMID: 38134771 DOI: 10.1103/physrevlett.131.236601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 11/02/2023] [Indexed: 12/24/2023]
Abstract
Relating the quantized Hall response of correlated insulators to many-body topological invariants is a key challenge in topological quantum matter. Here, we use Středa's formula to derive an expression for the many-body Chern number in terms of the single-particle interacting Green's function and its derivative with respect to a magnetic field. In this approach, we find that this many-body topological invariant can be decomposed in terms of two contributions, N_{3}[G]+ΔN_{3}[G], where N_{3}[G] is known as the Ishikawa-Matsuyama invariant and where the second term involves derivatives of Green's function and the self-energy with respect to the magnetic perturbation. As a by-product, the invariant N_{3}[G] is shown to stem from the derivative of Luttinger's theorem with respect to the probe magnetic field. These results reveal under which conditions the quantized Hall conductivity of correlated topological insulators is solely dictated by the invariant N_{3}[G], providing new insight on the origin of fractionalization in strongly correlated topological phases.
Collapse
Affiliation(s)
- Lucila Peralta Gavensky
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Subir Sachdev
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| |
Collapse
|
4
|
Léonard J, Kim S, Kwan J, Segura P, Grusdt F, Repellin C, Goldman N, Greiner M. Realization of a fractional quantum Hall state with ultracold atoms. Nature 2023; 619:495-499. [PMID: 37344594 DOI: 10.1038/s41586-023-06122-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/24/2023] [Indexed: 06/23/2023]
Abstract
Strongly interacting topological matter1 exhibits fundamentally new phenomena with potential applications in quantum information technology2,3. Emblematic instances are fractional quantum Hall (FQH) states4, in which the interplay of a magnetic field and strong interactions gives rise to fractionally charged quasi-particles, long-ranged entanglement and anyonic exchange statistics. Progress in engineering synthetic magnetic fields5-21 has raised the hope to create these exotic states in controlled quantum systems. However, except for a recent Laughlin state of light22, preparing FQH states in engineered systems remains elusive. Here we realize a FQH state with ultracold atoms in an optical lattice. The state is a lattice version of a bosonic ν = 1/2 Laughlin state4,23 with two particles on 16 sites. This minimal system already captures many hallmark features of Laughlin-type FQH states24-28: we observe a suppression of two-body interactions, we find a distinctive vortex structure in the density correlations and we measure a fractional Hall conductivity of σH/σ0 = 0.6(2) by means of the bulk response to a magnetic perturbation. Furthermore, by tuning the magnetic field, we map out the transition point between the normal and the FQH regime through a spectroscopic investigation of the many-body gap. Our work provides a starting point for exploring highly entangled topological matter with ultracold atoms29-33.
Collapse
Affiliation(s)
- Julian Léonard
- Department of Physics, Harvard University, Cambridge, MA, USA.
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Vienna, Austria.
| | - Sooshin Kim
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Joyce Kwan
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Perrin Segura
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Fabian Grusdt
- Department of Physics and ASC, Ludwig-Maximilians-Universität München, Munich, Germany
- Munich Center for Quantum Science and Technology (MCQST), Munich, Germany
| | | | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems (CENOLI), Université Libre de Bruxelles, Brussels, Belgium
| | - Markus Greiner
- Department of Physics, Harvard University, Cambridge, MA, USA
| |
Collapse
|
5
|
Mostaan N, Grusdt F, Goldman N. Quantized topological pumping of solitons in nonlinear photonics and ultracold atomic mixtures. Nat Commun 2022; 13:5997. [PMID: 36220824 PMCID: PMC9554178 DOI: 10.1038/s41467-022-33478-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 09/20/2022] [Indexed: 12/02/2022] Open
Abstract
Exploring the interplay between topological band structures and tunable nonlinearities has become possible with the development of synthetic lattice systems. In this emerging field of nonlinear topological physics, an experiment revealed the quantized motion of solitons in Thouless pumps and suggested that this phenomenon was dictated by the Chern number of the band from which solitons emanate. Here, we elucidate the origin of this nonlinear topological effect, by showing that the motion of solitons is established by the quantized displacement of the underlying Wannier functions. Our general theoretical approach, which fully clarifies the central role of the Chern number in solitonic pumps, provides a framework for describing the topological transport of nonlinear excitations in a broad class of physical systems. Exploiting this interdisciplinarity, we introduce an interaction-induced topological pump for ultracold atomic mixtures, where solitons of impurity atoms experience a quantized drift resulting from genuine interaction processes with their environment. Synthetic lattice systems are powerful platforms for studying the influence of intrinsic nonlinearities on topological phenomena. Here the authors elucidate the topological transport of solitons in terms of Wannier functions displacement and they introduce a nonlinearity-induced topological transport effect that could be observed in ultracold quantum mixtures.
Collapse
Affiliation(s)
- Nader Mostaan
- Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München, Theresienstr. 37, D-80333, München, Germany. .,Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799, München, Germany. .,CENOLI, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050, Brussels, Belgium.
| | - Fabian Grusdt
- Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München, Theresienstr. 37, D-80333, München, Germany.,Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799, München, Germany
| | - Nathan Goldman
- CENOLI, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050, Brussels, Belgium.
| |
Collapse
|
6
|
Goldman N, Kassamali B, Nwankwo C, Merola J, Cobos G, Vleugels R, LaChance A. 222 Geographic distribution of primary discoid lupus erythematosus and environmental hazards in Massachusetts. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
7
|
Abstract
Magnetic monopoles play a central role in areas of physics that range from electromagnetism to topological matter. String theory promotes conventional vector gauge fields of electrodynamics to tensor gauge fields and predicts the existence of more exotic tensor monopoles. Here, we report the synthesis of a tensor monopole in a four-dimensional parameter space defined by the spin degrees of freedom of a single solid-state defect in diamond. Using two complementary methods, we characterized the tensor monopole by measuring its quantized topological charge and its emanating Kalb-Ramond field. By introducing a fictitious external field that breaks chiral symmetry, we further observed an intriguing spectral transition, characterized by spectral rings protected by mirror symmetries. Our work demonstrates the possibility of emulating exotic topological structures inspired by string theory.
Collapse
Affiliation(s)
| | - Changhao Li
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Giandomenico Palumbo
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium.,School of Theoretical Physics, Dublin Institute for Advanced Studies, 10 Burlington Road, Dublin 4, Ireland
| | - Yan-Qing Zhu
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Paola Cappellaro
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
8
|
Fink DL, Khan PY, Goldman N, Cai J, Hone L, Mooney C, El-Shakankery KH, Sismey G, Whitford V, Marks M, Thomas S. Development and internal validation of a diagnostic prediction model for COVID-19 at time of admission to hospital. QJM 2021; 114:699-705. [PMID: 33165573 PMCID: PMC7717412 DOI: 10.1093/qjmed/hcaa305] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/15/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Early coronavirus disease 2019 (COVID-19) diagnosis prior to laboratory testing results is crucial for infection control in hospitals. Models exist predicting COVID-19 diagnosis, but significant concerns exist regarding methodology and generalizability. AIM To generate the first COVID-19 diagnosis risk score for use at the time of hospital admission using the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) checklist. DESIGN A multivariable diagnostic prediction model for COVID-19 using the TRIPOD checklist applied to a large single-centre retrospective observational study of patients with suspected COVID-19. METHODS 581 individuals were admitted with suspected COVID-19; the majority had laboratory-confirmed COVID-19 (420/581, 72.2%). Retrospective collection was performed of electronic clinical records and pathology data. RESULTS The final multivariable model demonstrated AUC 0.8535 (95% confidence interval 0.8121-0.8950). The final model used six clinical variables that are routinely available in most low and high-resource settings. Using a cut-off of 2, the derived risk score has a sensitivity of 78.1% and specificity of 86.8%. At COVID-19 prevalence of 10% the model has a negative predictive value (NPV) of 96.5%. CONCLUSIONS Our risk score is intended for diagnosis of COVID-19 in individuals admitted to hospital with suspected COVID-19. The score is the first developed for COVID-19 diagnosis using the TRIPOD checklist. It may be effective as a tool to rule out COVID-19 and function at different pandemic phases of variable COVID-19 prevalence. The simple score could be used by any healthcare worker to support hospital infection control prior to laboratory testing results.
Collapse
Affiliation(s)
- D L Fink
- Department of Infectious Diseases, Whipps Cross Hospital, Bart’s Health NHS Trust, London
- Corresponding author: Dr Douglas Fink, Department of Infectious Diseases, Whipps Cross University Hospital, Whipps Cross road, Leytonstone, London, E11 1NR; +447815142926
| | - P Y Khan
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London
| | - N Goldman
- Department of Respiratory Medicine, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| | - J Cai
- Department of Infectious Diseases, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| | - L Hone
- Department of Respiratory Medicine, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| | - C Mooney
- Department of Respiratory Medicine, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| | - K H El-Shakankery
- Department of Respiratory Medicine, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| | - G Sismey
- Department of Respiratory Medicine, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| | - V Whitford
- Department of Respiratory Medicine, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| | - M Marks
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London
| | - S Thomas
- Department of Infectious Diseases, Whipps Cross Hospital, Bart’s Health NHS Trust, London
- Department of Acute Medicine, Whipps Cross Hospital, Bart’s Health NHS Trust, London
| |
Collapse
|
9
|
Maiti A, Small W, Kroonblawd MP, Lewicki JP, Goldman N, Wilson TS, Saab AP. Constitutive Model of Radiation Aging Effects in Filled Silicone Elastomers under Strain. J Phys Chem B 2021; 125:10047-10057. [PMID: 34450004 DOI: 10.1021/acs.jpcb.1c04958] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Filled silicone elastomers, an essential component in many technological applications, are often subjected to controlled or unintended radiation for a variety of reasons. Radiation exposure can lead to permanent mechanical and structural changes in the material, which is manifested as altered mechanical response, and in some cases, a permanent set. For unfilled elastomers, network theories developed and refined over decades can explain these effects in terms of chain-scission and cross-link formation and a hypothesis involving independent networks formed at different strain levels of the material. Here, we expose a filled silicone rubber to gamma radiation while being under finite elongational strain and show that the observed mechanical and structural changes can be quantitatively modeled within the same theoretical framework developed for unfilled elastomers as long as nuances associated with the Mullins effect are accounted for in a consistent manner. In this work, we employ Ogden's incompressible hyperelastic model within the framework of Tobolsky's two-network scheme to describe the observed permanent set and mechanical modulus changes as a function of radiation dosage. In the process, we conclude that gamma radiation induces both direct cross-linking at chain crossings (H-links) and main-chain-scission followed by cross-linking (Y-links). We provide an estimate of the ratio of chain-scission to cross-linking rates, which is in reasonable agreement with previous experimental estimate from Charlesby-Pinner analysis. We use density functional theory (DFT)-based quantum mechanical calculations to explore the stability of -Si and -SiO radicals that form upon a radiation-induced chain-scission event, which sheds light on the relative rates of Y-linking and H-linking processes.
Collapse
Affiliation(s)
- A Maiti
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - W Small
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - M P Kroonblawd
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - J P Lewicki
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - N Goldman
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - T S Wilson
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - A P Saab
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| |
Collapse
|
10
|
Goldman N, Yefsah T. The Weyl side of ultracold matter. Science 2021; 372:234-235. [PMID: 33859019 DOI: 10.1126/science.abg0892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Nathan Goldman
- Interdisciplinary Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Tarik Yefsah
- Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, 24 rue Lhomond 75005 Paris, France.
| |
Collapse
|
11
|
Abstract
Bloch oscillations (BOs) are a fundamental phenomenon by which a wave packet undergoes a periodic motion in a lattice when subjected to a force. Observed in a wide range of synthetic systems, BOs are intrinsically related to geometric and topological properties of the underlying band structure. This has established BOs as a prominent tool for the detection of Berry-phase effects, including those described by non-Abelian gauge fields. In this work, we unveil a unique topological effect that manifests in the BOs of higher-order topological insulators through the interplay of non-Abelian Berry curvature and quantized Wilson loops. It is characterized by an oscillating Hall drift synchronized with a topologically-protected inter-band beating and a multiplied Bloch period. We elucidate that the origin of this synchronization mechanism relies on the periodic quantum dynamics of Wannier centers. Our work paves the way to the experimental detection of non-Abelian topological properties through the measurement of Berry phases and center-of-mass displacements.
Collapse
Affiliation(s)
- M Di Liberto
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, Brussels, B-1050, Belgium.
| | - N Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, Brussels, B-1050, Belgium
| | - G Palumbo
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, Brussels, B-1050, Belgium
| |
Collapse
|
12
|
Yu M, Yang P, Gong M, Cao Q, Lu Q, Liu H, Zhang S, Plenio MB, Jelezko F, Ozawa T, Goldman N, Cai J. Experimental measurement of the quantum geometric tensor using coupled qubits in diamond. Natl Sci Rev 2020; 7:254-260. [PMID: 34692040 PMCID: PMC8288884 DOI: 10.1093/nsr/nwz193] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/17/2019] [Accepted: 11/18/2019] [Indexed: 12/03/2022] Open
Abstract
Geometry and topology are fundamental concepts, which underlie a wide range of fascinating physical phenomena such as topological states of matter and topological defects. In quantum mechanics, the geometry of quantum states is fully captured by the quantum geometric tensor. Using a qubit formed by an NV center in diamond, we perform the first experimental measurement of the complete quantum geometric tensor. Our approach builds on a strong connection between coherent Rabi oscillations upon parametric modulations and the quantum geometry of the underlying states. We then apply our method to a system of two interacting qubits, by exploiting the coupling between the NV center spin and a neighboring 13C nuclear spin. Our results establish coherent dynamical responses as a versatile probe for quantum geometry, and they pave the way for the detection of novel topological phenomena in solid state.
Collapse
Affiliation(s)
- Min Yu
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Pengcheng Yang
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Musang Gong
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qingyun Cao
- Institut für Quantenoptik & IQST, Albert-Einstein Allee 11, Universität Ulm, D-89081 Ulm, Germany.,School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qiuyu Lu
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Haibin Liu
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shaoliang Zhang
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Martin B Plenio
- Institut für Theoretische Physik & IQST, Albert-Einstein Allee 11, Universität Ulm, D-89081 Ulm, Germany.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Fedor Jelezko
- Institut für Quantenoptik & IQST, Albert-Einstein Allee 11, Universität Ulm, D-89081 Ulm, Germany.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Tomoki Ozawa
- Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), RIKEN, Wako, Saitama 351-0198, Japan
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, B-1050 Brussels, Belgium
| | - Jianming Cai
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.,International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| |
Collapse
|
13
|
Barbiero L, Schweizer C, Aidelsburger M, Demler E, Goldman N, Grusdt F. Coupling ultracold matter to dynamical gauge fields in optical lattices: From flux attachment to ℤ 2 lattice gauge theories. Sci Adv 2019; 5:eaav7444. [PMID: 31646173 PMCID: PMC6788866 DOI: 10.1126/sciadv.aav7444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 09/18/2019] [Indexed: 05/16/2023]
Abstract
From the standard model of particle physics to strongly correlated electrons, various physical settings are formulated in terms of matter coupled to gauge fields. Quantum simulations based on ultracold atoms in optical lattices provide a promising avenue to study these complex systems and unravel the underlying many-body physics. Here, we demonstrate how quantized dynamical gauge fields can be created in mixtures of ultracold atoms in optical lattices, using a combination of coherent lattice modulation with strong interactions. Specifically, we propose implementation of ℤ2 lattice gauge theories coupled to matter, reminiscent of theories previously introduced in high-temperature superconductivity. We discuss a range of settings from zero-dimensional toy models to ladders featuring transitions in the gauge sector to extended two-dimensional systems. Mastering lattice gauge theories in optical lattices constitutes a new route toward the realization of strongly correlated systems, with properties dictated by an interplay of dynamical matter and gauge fields.
Collapse
Affiliation(s)
- Luca Barbiero
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Christian Schweizer
- Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstr. 4, 80799 München, Germany
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799 München Germany
| | - Monika Aidelsburger
- Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstr. 4, 80799 München, Germany
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799 München Germany
| | - Eugene Demler
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Fabian Grusdt
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799 München Germany
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- Department of Physics, Technical University of Munich, 85748, Garching, Germany
| |
Collapse
|
14
|
Abstract
Great efforts are currently devoted to the engineering of topological Bloch bands in ultracold atomic gases. Recent achievements in this direction, together with the possibility of tuning interparticle interactions, suggest that strongly correlated states reminiscent of fractional quantum Hall (FQH) liquids could soon be generated in these systems. In this experimental framework, where transport measurements are limited, identifying unambiguous signatures of FQH-type states constitutes a challenge on its own. Here, we demonstrate that the fractional nature of the quantized Hall conductance, a fundamental characteristic of FQH states, could be detected in ultracold gases through a circular-dichroic measurement, namely, by monitoring the energy absorbed by the atomic cloud upon a circular drive. We validate this approach by comparing the circular-dichroic signal to the many-body Chern number and discuss how such measurements could be performed to distinguish FQH-type states from competing states. Our scheme offers a practical tool for the detection of topologically ordered states in quantum-engineered systems, with potential applications in solid state.
Collapse
Affiliation(s)
- C Repellin
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - N Goldman
- CENOLI, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| |
Collapse
|
15
|
Boulier T, Maslek J, Bukov M, Bracamontes C, Magnan E, Lellouch S, Demler E, Goldman N, Porto JV. Parametric heating in a 2D periodically-driven bosonic system: Beyond the weakly-interacting regime. Phys Rev X 2019; 9:10.1103/physrevx.9.011047. [PMID: 32117577 PMCID: PMC7047775 DOI: 10.1103/physrevx.9.011047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We experimentally investigate the effects of parametric instabilities on the short-time heating process of periodically-driven bosons in 2D optical lattices with a continuous transverse (tube) degree of freedom. We analyze three types of periodic drives: (i) linear along the x-lattice direction only, (ii) linear along the lattice diagonal, and (iii) circular in the lattice plane. In all cases, we demonstrate that the BEC decay is dominated by the emergence of unstable Bogoliubov modes, rather than scattering in higher Floquet bands, in agreement with recent theoretical predictions. The observed BEC depletion rates are much higher when shaking both along x and y directions, as opposed to only x or only y. We also report an explosion of the decay rates at large drive amplitudes, and suggest a phenomenological description beyond Bogoliubov theory. In this strongly-coupled regime, circular drives heat faster than diagonal drives, which illustrates the non-trivial dependence of the heating on the choice of drive.
Collapse
Affiliation(s)
- T. Boulier
- Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, College Park, Maryland 20742 USA
- Laboratoire Charles Fabry, Institut dOptique Graduate School, CNRS, Université Paris-Saclay, 91127 Palaiseau cedex, France
| | - J. Maslek
- Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, College Park, Maryland 20742 USA
| | - M. Bukov
- Department of Physics, University of California Berkeley, CA 94720, USA
| | - C. Bracamontes
- Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, College Park, Maryland 20742 USA
| | - E. Magnan
- Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, College Park, Maryland 20742 USA
- Laboratoire Charles Fabry, Institut dOptique Graduate School, CNRS, Université Paris-Saclay, 91127 Palaiseau cedex, France
| | - S. Lellouch
- Laboratoire de Physique des Lasers, Atomes et Molcules, Université Lille 1 Sciences et Technologies, CNRS; F-59655 Villeneuve d’Ascq Cedex, France
| | - E. Demler
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - N. Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - J. V. Porto
- Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, College Park, Maryland 20742 USA
| |
Collapse
|
16
|
Abstract
Monopoles are intriguing topological objects, which play a central role in gauge theories and topological states of matter. While conventional monopoles are found in odd-dimensional flat spaces, such as the Dirac monopole in three dimensions and the non-Abelian Yang monopole in five dimensions, more exotic objects were predicted to exist in even dimensions. This is the case of "tensor monopoles," which are associated with tensor (Kalb-Ramond) gauge fields, and which can be defined in four-dimensional flat spaces. In this work, we investigate the possibility of creating and measuring such a tensor monopole in condensed-matter physics by introducing a realistic three-band model defined over a four-dimensional parameter space. Our probing method is based on the observation that the topological charge of this tensor monopole, which we relate to a generalized Berry curvature, can be directly extracted from the quantum metric. We propose a realistic three-level atomic system, where tensor monopoles could be generated and revealed through quantum-metric measurements.
Collapse
Affiliation(s)
- Giandomenico Palumbo
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| |
Collapse
|
17
|
Mukherjee S, Chandrasekharan HK, Öhberg P, Goldman N, Thomson RR. State-recycling and time-resolved imaging in topological photonic lattices. Nat Commun 2018; 9:4209. [PMID: 30310062 PMCID: PMC6181942 DOI: 10.1038/s41467-018-06723-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/19/2018] [Indexed: 11/13/2022] Open
Abstract
Photonic lattices—arrays of optical waveguides—are powerful platforms for simulating a range of phenomena, including topological phases. While probing dynamics is possible in these systems, by reinterpreting the propagation direction as time, accessing long timescales constitutes a severe experimental challenge. Here, we overcome this limitation by placing the photonic lattice in a cavity, which allows the optical state to evolve through the lattice multiple times. The accompanying detection method, which exploits a multi-pixel single-photon detector array, offers quasi-real time-resolved measurements after each round trip. We apply the state-recycling scheme to intriguing photonic lattices emulating Dirac fermions and Floquet topological phases. We also realise a synthetic pulsed electric field, which can be used to drive transport within photonic lattices. This work opens an exciting route towards the detection of long timescale effects in engineered photonic lattices and the realisation of hybrid analogue-digital simulators. Topological effects can be emulated using photonic lattices where the length of a waveguide represents time, which is often limited by fabrication constraints. Here, Mukherjee et al. exploit a single-photon detector array enabled state-recycling scheme to increase the accessible time scale.
Collapse
Affiliation(s)
- Sebabrata Mukherjee
- Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences (IPaQS), School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Harikumar K Chandrasekharan
- Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences (IPaQS), School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Patrik Öhberg
- Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences (IPaQS), School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, 1050, Brussels, Belgium.
| | - Robert R Thomson
- Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences (IPaQS), School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| |
Collapse
|
18
|
Mukherjee S, Di Liberto M, Öhberg P, Thomson RR, Goldman N. Experimental Observation of Aharonov-Bohm Cages in Photonic Lattices. Phys Rev Lett 2018; 121:075502. [PMID: 30169066 DOI: 10.1103/physrevlett.121.075502] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Indexed: 06/08/2023]
Abstract
We report on the experimental realization of a uniform synthetic magnetic flux and the observation of Aharonov-Bohm cages in photonic lattices. Considering a rhombic array of optical waveguides, we engineer modulation-assisted tunneling processes that effectively produce nonzero magnetic flux per plaquette. This synthetic magnetic field for light can be tuned at will by varying the phase of the modulation. In the regime where half a flux quantum is realized in each plaquette, all the energy bands dramatically collapse into nondispersive (flat) bands and all eigenstates are completely localized. We demonstrate this Aharonov-Bohm caging by studying the propagation of light in the bulk of the photonic lattice. Besides, we explore the dynamics on the edge of the lattice and discuss how the corresponding edge states can be continuously connected to the topological edge states of the Creutz ladder. Our photonic lattice constitutes an appealing platform where the interplay between engineered gauge fields, frustration, localization, and topological properties can be finely studied.
Collapse
Affiliation(s)
- Sebabrata Mukherjee
- Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Marco Di Liberto
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Patrik Öhberg
- Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Robert R Thomson
- Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| |
Collapse
|
19
|
Tran DT, Dauphin A, Grushin AG, Zoller P, Goldman N. Probing topology by "heating": Quantized circular dichroism in ultracold atoms. Sci Adv 2017; 3:e1701207. [PMID: 28835930 PMCID: PMC5562418 DOI: 10.1126/sciadv.1701207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 07/16/2017] [Indexed: 05/30/2023]
Abstract
We reveal an intriguing manifestation of topology, which appears in the depletion rate of topological states of matter in response to an external drive. This phenomenon is presented by analyzing the response of a generic two-dimensional (2D) Chern insulator subjected to a circular time-periodic perturbation. Because of the system's chiral nature, the depletion rate is shown to depend on the orientation of the circular shake; taking the difference between the rates obtained from two opposite orientations of the drive, and integrating over a proper drive-frequency range, provides a direct measure of the topological Chern number (ν) of the populated band: This "differential integrated rate" is directly related to the strength of the driving field through the quantized coefficient η0 = ν/ℏ2, where h = 2π ℏ is Planck's constant. Contrary to the integer quantum Hall effect, this quantized response is found to be nonlinear with respect to the strength of the driving field, and it explicitly involves interband transitions. We investigate the possibility of probing this phenomenon in ultracold gases and highlight the crucial role played by edge states in this effect. We extend our results to 3D lattices, establishing a link between depletion rates and the nonlinear photogalvanic effect predicted for Weyl semimetals. The quantized circular dichroism revealed in this work designates depletion rate measurements as a universal probe for topological order in quantum matter.
Collapse
Affiliation(s)
- Duc Thanh Tran
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Alexandre Dauphin
- ICFO–Institut de Ciencies Fotoniques, Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Adolfo G. Grushin
- Department of Physics, University of California, Berkeley, CA 94720, USA
- Institut Néel, CNRS and Université Grenoble Alpes, F-38042 Grenoble, France
| | - Peter Zoller
- International Solvay Institutes, Université Libre de Bruxelles, Campus Plaine, B-1050 Brussels, Belgium
- Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| |
Collapse
|
20
|
Goldman N, Loebinger MR, Wilson R. Long-term antibiotic treatment for non-cystic fibrosis bronchiectasis in adults: evidence, current practice and future use. Expert Rev Respir Med 2016; 10:1259-1268. [DOI: 10.1080/17476348.2016.1258304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
21
|
|
22
|
Price HM, Zilberberg O, Ozawa T, Carusotto I, Goldman N. Four-Dimensional Quantum Hall Effect with Ultracold Atoms. Phys Rev Lett 2015; 115:195303. [PMID: 26588394 DOI: 10.1103/physrevlett.115.195303] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Indexed: 06/05/2023]
Abstract
We propose a realistic scheme to detect the 4D quantum Hall effect using ultracold atoms. Based on contemporary technology, motion along a synthetic fourth dimension can be accomplished through controlled transitions between internal states of atoms arranged in a 3D optical lattice. From a semiclassical analysis, we identify the linear and nonlinear quantized current responses of our 4D model, relating these to the topology of the Bloch bands. We then propose experimental protocols, based on current or center-of-mass-drift measurements, to extract the topological second Chern number. Our proposal sets the stage for the exploration of novel topological phases in higher dimensions.
Collapse
Affiliation(s)
- H M Price
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Italy
| | - O Zilberberg
- Institute for Theoretical Physics, ETH Zurich, 8093 Zürich, Switzerland
| | - T Ozawa
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Italy
| | - I Carusotto
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Italy
| | - N Goldman
- CENOLI, Faculté des Sciences, Université Libre de Bruxelles (U.L.B.), B-1050 Brussels, Belgium
| |
Collapse
|
23
|
Nascimbene S, Goldman N, Cooper NR, Dalibard J. Dynamic Optical Lattices of Subwavelength Spacing for Ultracold Atoms. Phys Rev Lett 2015; 115:140401. [PMID: 26551796 DOI: 10.1103/physrevlett.115.140401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Indexed: 06/05/2023]
Abstract
We propose a scheme for realizing lattice potentials of subwavelength spacing for ultracold atoms. It is based on spin-dependent optical lattices with a time-periodic modulation. We show that the atomic motion is well described by the combined action of an effective, time-independent lattice of small spacing, together with a micromotion associated with the time modulation. A numerical simulation shows that an atomic gas can be adiabatically loaded into the effective lattice ground state, for time scales comparable to the ones required for adiabatic loading of standard optical lattices. We generalize our scheme to a two-dimensional geometry, leading to Bloch bands with nonzero Chern numbers. The realization of lattices of subwavelength spacing allows for the enhancement of energy scales, which could facilitate the achievement of strongly correlated (topological) states.
Collapse
Affiliation(s)
- Sylvain Nascimbene
- Laboratoire Kastler Brossel, Collège de France, ENS-PSL Research University, CNRS, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - Nathan Goldman
- Laboratoire Kastler Brossel, Collège de France, ENS-PSL Research University, CNRS, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
- CENOLI, Faculté des Sciences, Université Libre de Bruxelles (ULB), B-1050 Brussels, Belgium
| | - Nigel R Cooper
- T.C.M. Group, Cavendish Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Jean Dalibard
- Laboratoire Kastler Brossel, Collège de France, ENS-PSL Research University, CNRS, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| |
Collapse
|
24
|
Alexander M, Durham CF, Hooper JI, Jeffries PR, Goldman N, Kardong-Edgren S“S, Kesten KS, Spector N, Tagliareni E, Radtke B, Tillman C. NCSBN Simulation Guidelines for Prelicensure Nursing Programs. Journal of Nursing Regulation 2015. [DOI: 10.1016/s2155-8256(15)30783-3] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
25
|
Abstract
Gauge fields are central in our modern understanding of physics at all scales. At the highest energy scales known, the microscopic universe is governed by particles interacting with each other through the exchange of gauge bosons. At the largest length scales, our Universe is ruled by gravity, whose gauge structure suggests the existence of a particle-the graviton-that mediates the gravitational force. At the mesoscopic scale, solid-state systems are subjected to gauge fields of different nature: materials can be immersed in external electromagnetic fields, but they can also feature emerging gauge fields in their low-energy description. In this review, we focus on another kind of gauge field: those engineered in systems of ultracold neutral atoms. In these setups, atoms are suitably coupled to laser fields that generate effective gauge potentials in their description. Neutral atoms 'feeling' laser-induced gauge potentials can potentially mimic the behavior of an electron gas subjected to a magnetic field, but also, the interaction of elementary particles with non-Abelian gauge fields. Here, we review different realized and proposed techniques for creating gauge potentials-both Abelian and non-Abelian-in atomic systems and discuss their implication in the context of quantum simulation. While most of these setups concern the realization of background and classical gauge potentials, we conclude with more exotic proposals where these synthetic fields might be made dynamical, in view of simulating interacting gauge theories with cold atoms.
Collapse
Affiliation(s)
- N Goldman
- College de France, 11 place Marcelin Berthelot & Laboratoire Kastler Brossel, CNRS, UPMC, ENS, 24 rue Lhomond, 75005 Paris, France
| | | | | | | |
Collapse
|
26
|
Chowdhry VK, Chowdhry AK, Goldman N, Scalzetti EM, Grage RA, Bogart JA. Complications From Computed Tomography–Guided Core Needle Biopsy for Patients Receiving Stereotactic Body Radiation Therapy for Early-Stage Lesions of the Lung. Clin Lung Cancer 2014; 15:302-6. [DOI: 10.1016/j.cllc.2014.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 03/13/2014] [Accepted: 04/08/2014] [Indexed: 10/25/2022]
|
27
|
Celi A, Massignan P, Ruseckas J, Goldman N, Spielman IB, Juzeliūnas G, Lewenstein M. Synthetic gauge fields in synthetic dimensions. Phys Rev Lett 2014; 112:043001. [PMID: 24580445 DOI: 10.1103/physrevlett.112.043001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Indexed: 05/22/2023]
Abstract
We describe a simple technique for generating a cold-atom lattice pierced by a uniform magnetic field. Our method is to extend a one-dimensional optical lattice into the "dimension" provided by the internal atomic degrees of freedom, yielding a synthetic two-dimensional lattice. Suitable laser coupling between these internal states leads to a uniform magnetic flux within the two-dimensional lattice. We show that this setup reproduces the main features of magnetic lattice systems, such as the fractal Hofstadter-butterfly spectrum and the chiral edge states of the associated Chern insulating phases.
Collapse
Affiliation(s)
- A Celi
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, E-08860 Castelldefels (Barcelona), Spain
| | - P Massignan
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, E-08860 Castelldefels (Barcelona), Spain
| | - J Ruseckas
- Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania
| | - N Goldman
- Laboratoire Kastler Brossel, CNRS, UPMC, ENS, 24 rue Lhomond, F-75005 Paris, France
| | - I B Spielman
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742-4111, USA and National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - G Juzeliūnas
- Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania
| | - M Lewenstein
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, E-08860 Castelldefels (Barcelona), Spain and ICREA-Institució Catalana de Recerca i Estudis Avançats, E-08010 Barcelona, Spain
| |
Collapse
|
28
|
Dauphin A, Goldman N. Extracting the Chern number from the dynamics of a Fermi gas: implementing a quantum Hall bar for cold atoms. Phys Rev Lett 2013; 111:135302. [PMID: 24116789 DOI: 10.1103/physrevlett.111.135302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 08/03/2013] [Indexed: 06/02/2023]
Abstract
We propose a scheme to measure the quantized Hall conductivity of an ultracold Fermi gas initially prepared in a topological Chern insulating phase and driven by a constant force. We show that the time evolution of the center of mass, after releasing the cloud, provides a direct and clear signature of the topologically invariant Chern number. We discuss the validity of this scheme, highlighting the importance of driving the system with a sufficiently strong force to displace the cloud over measurable distances while avoiding band-mixing effects. The unusual shapes of the driven atomic cloud are qualitatively discussed in terms of a semiclassical approach.
Collapse
Affiliation(s)
- Alexandre Dauphin
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium and Departamento de Física Teórica I, Universidad Complutense, 28040 Madrid, Spain
| | | |
Collapse
|
29
|
Goldman N, Wright J, Lewin S, Herzog T, Burke W. Rate of bowel herniation in patients undergoing robotic surgery. Gynecol Oncol 2013. [DOI: 10.1016/j.ygyno.2013.04.436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
30
|
Veenith T, Sanfilippo F, Ercole A, Carter E, Goldman N, Bradley P, Gunning K, Burnstein R. Nosocomial H1N1 infection during 2010–2011 pandemic: a retrospective cohort study from a tertiary referral hospital. J Hosp Infect 2012; 81:202-5. [DOI: 10.1016/j.jhin.2012.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 04/09/2012] [Indexed: 11/26/2022]
|
31
|
Abstract
We propose a realistic scheme to detect topological edge states in an optical lattice subjected to a synthetic magnetic field, based on a generalization of Bragg spectroscopy sensitive to angular momentum. We demonstrate that using a well-designed laser probe, the Bragg spectra provide an unambiguous signature of the topological edge states that establishes their chiral nature. This signature is present for a variety of boundaries, from a hard wall to a smooth harmonic potential added on top of the optical lattice. Experimentally, the Bragg signal should be very weak. To make it detectable, we introduce a "shelving method," based on Raman transitions, which transfers angular momentum and changes the internal atomic state simultaneously. This scheme allows us to detect the weak signal from the selected edge states on a dark background, and drastically improves the detectivity. It also leads to the possibility to directly visualize the topological edge states, using in situ imaging, offering a unique and instructive view on topological insulating phases.
Collapse
Affiliation(s)
- Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, B-1050 Brussels, Belgium.
| | | | | |
Collapse
|
32
|
Jordan G, Goldman N. The Effects of Alignment Error and Alignment Filtering on the Sitewise Detection of Positive Selection. Mol Biol Evol 2011; 29:1125-39. [DOI: 10.1093/molbev/msr272] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
33
|
Goldman N, Satija I, Nikolic P, Bermudez A, Martin-Delgado MA, Lewenstein M, Spielman IB. Realistic time-reversal invariant topological insulators with neutral atoms. Phys Rev Lett 2010; 105:255302. [PMID: 21231599 DOI: 10.1103/physrevlett.105.255302] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 10/26/2010] [Indexed: 05/30/2023]
Abstract
We lay out an experiment to realize time-reversal invariant topological insulators in alkali atomic gases. We introduce an original method to synthesize a gauge field in the near field of an atom chip, which effectively mimics the effects of spin-orbit coupling and produces quantum spin-Hall states. We also propose a feasible scheme to engineer sharp boundaries where the hallmark edge states are localized. Our multiband system has a large parameter space exhibiting a variety of quantum phase transitions between topological and normal insulating phases. Because of their remarkable versatility, cold-atom systems are ideally suited to realize topological states of matter and drive the development of topological quantum computing.
Collapse
Affiliation(s)
- N Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, B-1050 Brussels, Belgium
| | | | | | | | | | | | | |
Collapse
|
34
|
Bermudez A, Mazza L, Rizzi M, Goldman N, Lewenstein M, Martin-Delgado MA. Wilson fermions and axion electrodynamics in optical lattices. Phys Rev Lett 2010; 105:190404. [PMID: 21231153 DOI: 10.1103/physrevlett.105.190404] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 09/03/2010] [Indexed: 05/28/2023]
Abstract
We show that ultracold Fermi gases in optical superlattices can be used as quantum simulators of relativistic lattice fermions in 3+1 dimensions. By exploiting laser-assisted tunneling, we find an analogue of the so-called naive Dirac fermions, and thus provide a realization of the fermion doubling problem. Moreover, we show how to implement Wilson fermions, and discuss how their mass can be inverted by tuning the laser intensities. In this regime, our atomic gas corresponds to a phase of matter where Maxwell electrodynamics is replaced by axion electrodynamics: a 3D topological insulator.
Collapse
Affiliation(s)
- A Bermudez
- Departamento de Física Teórica I, Universidad Complutense, 28040 Madrid, Spain
| | | | | | | | | | | |
Collapse
|
35
|
Buttenheim AM, Wong R, Goldman N, Pebley AR. Does social status predict adult smoking and obesity? Results from the 2000 Mexican National Health Survey. Glob Public Health 2010; 5:413-26. [PMID: 19367478 DOI: 10.1080/17441690902756062] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Socioeconomic status is generally associated with better health, but recent evidence suggests that this 'social gradient' in health is far from universal. This study examines whether social gradients in smoking and obesity in Mexico - a country in the midst of rapid socioeconomic change - conform to or diverge from results for richer countries. Using a nationally representative sample of 39,129 Mexican adults, we calculate the odds of smoking and of being obese by educational attainment and by household wealth. We conclude that socioeconomic determinants of smoking and obesity in Mexico are complex, with some flat gradients and some strong positive or negative gradients. Higher social status (education and assets) is associated with more smoking and less obesity for urban women. Higher status rural women also smoke more, but obesity for these women has a non-linear relationship to education. For urban men, higher asset levels (but not education) are associated with obesity, whereas education is protective of smoking. Higher status rural men with more assets are more likely to smoke and be obese. As household wealth, education and urbanisation continue to increase in Mexico, these patterns suggest potential targets for public health intervention now and in the future.
Collapse
Affiliation(s)
- A M Buttenheim
- Office of Population Research, Princeton University, Princeton, NJ, USA.
| | | | | | | |
Collapse
|
36
|
Fleckenstein J, Irnich D, Goldman N, Chen M, Fujita T, Xu Q, Peng W, Liu W, Jensen T, Pei Y, Wang F, Han X, Chen J, Schnermann J, Takano T, Bekar L, Tieu K, Nedergaard M. Adenosine A1 receptors mediate local anti-nociceptive effects of acupuncture. Deutsche Zeitschrift für Akupunktur 2010. [DOI: 10.1016/j.dza.2010.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
37
|
Goldman N, Kubasiak A, Bermudez A, Gaspard P, Lewenstein M, Martin-Delgado MA. Non-Abelian optical lattices: anomalous quantum Hall effect and Dirac fermions. Phys Rev Lett 2009; 103:035301. [PMID: 19659289 DOI: 10.1103/physrevlett.103.035301] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 05/29/2009] [Indexed: 05/28/2023]
Abstract
We study the properties of an ultracold Fermi gas loaded in an optical square lattice and subjected to an external and classical non-Abelian gauge field. We show that this system can be exploited as an optical analogue of relativistic quantum electrodynamics, offering a remarkable route to access the exotic properties of massless Dirac fermions with cold atoms experiments. In particular, we show that the underlying Minkowski space-time can also be modified, reaching anisotropic regimes where a remarkable anomalous quantum Hall effect and a squeezed Landau vacuum could be observed.
Collapse
Affiliation(s)
- N Goldman
- Center for Nonlinear Phenomena and Complex Systems-Université Libre de Bruxelles (U.L.B.), Code Postal 231, Campus Plaine, B-1050 Brussels, Belgium
| | | | | | | | | | | |
Collapse
|
38
|
Fernandes R, Cusano A, Goldman N. One flap reconstruction of bilateral buccal mucosa and floor of mouth with a radial forearm free flap: “the aviator flap” design. Int J Oral Maxillofac Surg 2009. [DOI: 10.1016/j.ijom.2009.03.423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
39
|
Fernandes R, Cusano A, Goldman N. Use of the internal mammary artery perforator flap for pharyngocutaneous fistulas in the vessel depleted neck. Int J Oral Maxillofac Surg 2009. [DOI: 10.1016/j.ijom.2009.03.422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
40
|
Fernandes R, Cusano A, Goldman N. Reconstruction of mandibular defects secondary to ameloblastoma resection: a case for immediate reconstruction with free tissue transfer. Int J Oral Maxillofac Surg 2009. [DOI: 10.1016/j.ijom.2009.03.424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
41
|
Cusano A, Fernandes R, Goldman N. Maxillary reconstruction: the role of the fibula free flap. Int J Oral Maxillofac Surg 2009. [DOI: 10.1016/j.ijom.2009.03.419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
42
|
Mei Y, Cannizzaro C, Park H, Xu Q, Bogatyrev SR, Yi K, Goldman N, Langer R, Anderson DG. Cell-compatible, multicomponent protein arrays with subcellular feature resolution. Small 2008. [PMID: 18844310 PMCID: PMC2679812 DOI: 10.1002/smll] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- Ying Mei
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Mei Y, Cannizzaro C, Park H, Xu Q, Bogatyrev S, Yi K, Goldman N, Langer R, Anderson DG. Cell-compatible, multicomponent protein arrays with subcellular feature resolution. Small 2008; 4:1600-4. [PMID: 18844310 PMCID: PMC2679812 DOI: 10.1002/smll.200800363] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Ying Mei
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
| | - Christopher Cannizzaro
- Health Science and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
| | - Hyoungshin Park
- Department of Surgery, Massachusetts General Hospital, One Bowdoin Square, 11th floor, Boston, MA 02114 (USA)
| | - Qiaobing Xu
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
| | - Said Bogatyrev
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
| | - Kevin Yi
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
| | - Nathan Goldman
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
| | - Robert Langer
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
| | - Daniel G. Anderson
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 45 Carleton Street, Building E25-342, Cambridge, Massachusetts 02142 (USA), E-mail:
| |
Collapse
|
44
|
Abstract
The log-det estimator is a measure of divergence (evolutionary distance) between sequences of biological characters, DNA or amino acids, for example, and has been shown to be robust to biases in composition that can cause problems for other estimators. We provide a statistical framework to construct high-accuracy confidence intervals for log-det estimates and compare the efficiency of the estimator to that of maximum likelihood using time-reversible Markov models. The log-det estimator is found to have good statistical properties under such general models.
Collapse
Affiliation(s)
- T Massingham
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, UK.
| | | |
Collapse
|
45
|
|
46
|
Fernandes R, Lee J, Goldman N, Isaacs J, Rayner E, Malyapa R. O200 Cervical metastasis from maxillary alveolar squamous cell carcinoma. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s1744-7895(07)70278-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
47
|
Goldman N, Fellers RS, Brown MG, Braly LB, Keoshian CJ, Leforestier C, Saykally RJ. Spectroscopic determination of the water dimer intermolecular potential-energy surface. J Chem Phys 2002. [DOI: 10.1063/1.1476932] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
|
48
|
Stork G, Rosen P, Goldman N, Coombs RV, Tsuji J. Alkylation and Carbonation of Ketones by Trapping the Enolates from the Reduction of α,β-Unsaturated Ketones. J Am Chem Soc 2002. [DOI: 10.1021/ja01080a025] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
49
|
Goldman N. Social inequalities in health disentangling the underlying mechanisms. Ann N Y Acad Sci 2001; 954:118-39. [PMID: 11797854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Differentials in health and longevity by socioeconomic status and by the nature of social relationships have been found in innumerable studies in the social and medical sciences. Three categories of explanations for the observed patterns have been proposed: causal mechanisms through which the social environment affects health status or the risk of dying; selection or reverse causal pathways whereby a person's health status affects their social position; and artifactual mechanisms, such as measurement error. The general consensus among researchers is that the observed disparities in health are driven largely by a complex set of causal processes rather than by selection or by artifactual mechanisms. This paper explores the set of arguments and strategies that researchers have used to arrive at this conclusion. As part of this undertaking, we assess whether inferences regarding the minor contribution of selection to the overall association between social factors and health are justifiable. In addition, we identify current avenues of research that are providing new insights into the causal pathways linking social factors and health.
Collapse
Affiliation(s)
- N Goldman
- Office of Population Research, Princeton University, New Jersey 08544, USA.
| |
Collapse
|
50
|
Keutsch FN, Goldman N, Karyakin EN, Harker HA, Sanz ME, Leforestier C, Saykally RJ. Complete characterization of the (D2O)2 ground state: high Ka rotation-tunneling levels. Faraday Discuss 2001:79-93; discussion 109-19. [PMID: 11605283 DOI: 10.1039/b008825k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the observation of extensive a- and c-type rotation-tunneling (RT) spectra of (D2O)2 for Ka = 0-4. These data allow quantification of molecular constants and tunneling splittings for a number of previously unobserved RT states of (D2O)2. The vibrational ground state has thus been characterized to energies as high as those of some of the intermolecular vibrations, and we present the first test of the VRT(ASP-W) potential at these high Ka states.
Collapse
Affiliation(s)
- F N Keutsch
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, USA
| | | | | | | | | | | | | |
Collapse
|