Abstract:
:The Haldane model on a honeycomb lattice is a paradigmatic example of a Hamiltonian featuring topologically distinct phases of matter. It describes a mechanism through which a quantum Hall effect can appear as an intrinsic property of a band structure, rather than being caused by an external magnetic field. Although physical implementation has been considered unlikely, the Haldane model has provided the conceptual basis for theoretical and experimental research exploring topological insulators and superconductors. Here we report the experimental realization of the Haldane model and the characterization of its topological band structure, using ultracold fermionic atoms in a periodically modulated optical honeycomb lattice. The Haldane model is based on breaking both time-reversal symmetry and inversion symmetry. To break time-reversal symmetry, we introduce complex next-nearest-neighbour tunnelling terms, which we induce through circular modulation of the lattice position. To break inversion symmetry, we create an energy offset between neighbouring sites. Breaking either of these symmetries opens a gap in the band structure, which we probe using momentum-resolved interband transitions. We explore the resulting Berry curvatures, which characterize the topology of the lowest band, by applying a constant force to the atoms and find orthogonal drifts analogous to a Hall current. The competition between the two broken symmetries gives rise to a transition between topologically distinct regimes. By identifying the vanishing gap at a single Dirac point, we map out this transition line experimentally and quantitatively compare it to calculations using Floquet theory without free parameters. We verify that our approach, which allows us to tune the topological properties dynamically, is suitable even for interacting fermionic systems. Furthermore, we propose a direct extension to realize spin-dependent topological Hamiltonians.
journal_name
Naturejournal_title
Natureauthors
Jotzu G,Messer M,Desbuquois R,Lebrat M,Uehlinger T,Greif D,Esslinger Tdoi
10.1038/nature13915subject
Has Abstractpub_date
2014-11-13 00:00:00pages
237-40issue
7526eissn
0028-0836issn
1476-4687pii
nature13915journal_volume
515pub_type
杂志文章相关文献
NATURE文献大全abstract::Microtubules have a central role in eukaryotic cell polarity, in part through interactions between microtubule end-binding proteins and the cell cortex. In the fission yeast Schizosaccharomyces pombe, microtubules and the polarity modulator tea1p maintain cylindrical cell shape and strictly antipodal cell growth. The ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature01672
更新日期:2003-06-05 00:00:00
abstract::After observation of detailed structural evidence for the origin of birds from dinosaurs, and in light of evidence that dinosaur bone tissue resembles the histology in mammals, the histology of bone has become one of the focal points in discussions of the physiology of dinosaurs and Mesozoic birds. Most of this micros...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/35020550
更新日期:2000-08-10 00:00:00
abstract::Since the discovery of insulin nearly 70 years ago, there has been no problem more fundamental to diabetes research than understanding how insulin works at the cellular level. Insulin binds to the alpha subunit of the insulin receptor which activates the tyrosine kinase in the beta subunit, but the molecular events li...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/352073a0
更新日期:1991-07-04 00:00:00
abstract::Curare has long been regarded as a typical competitive antagonist of acetylcholine (ACh) at the vertebrate neuromuscular junction. Recently, however, it has been shown that curare can also block the channels opened by ACh at the frog neuromuscular junction as well as on rat and Aplysia neurones; moreover, curare is ab...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/298272a0
更新日期:1982-07-15 00:00:00
abstract::Large-scale systematic sequencing has generally depended on the availability of an ordered library of large-insert bacterial or viral genomic clones for the organism under study. The generation of these large insert libraries, and the location of each clone on a genome map, is a laborious and time-consuming process. I...
journal_title:Nature
pub_type: 杂志文章
doi:
更新日期:1997-05-29 00:00:00
abstract::In order to understand the dynamics of the India Asia collision zone, it is important to know the strain distribution in Central Asia, whose determination relies on the slip rates for active faults. Many previous slip-rate estimates of faults in Central Asia were based on the assumption that offset landforms are young...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/417428a
更新日期:2002-05-23 00:00:00
abstract::Antifreeze proteins provide fish with protection against the freezing effect of polar environments by binding to ice surfaces and inhibiting growth of ice crystals. We present the X-ray crystal structure at 1.5 A resolution of a lone alpha-helical antifreeze protein from winter flounder, which provides a detailed look...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/375427a0
更新日期:1995-06-01 00:00:00
abstract::The rapid development of the silk glands of Bombyx mori during the last larval instar shows two phases. During the first 4 days, in both the middle and posterior parts of the silk glands, the ribosomal machinery is assembled and the synthesis of housekeeping proteins starts. During the second phase (the last 4 days), ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/290267a0
更新日期:1981-03-19 00:00:00
abstract::Wolbachia is a common maternally inherited bacterial symbiont able to induce crossing sterilities known as cytoplasmic incompatibility (CI) in insects. Wolbachia-modified sperm are unable to complete fertilization of uninfected ova, but a rescue function allows infected eggs to develop normally. By providing a reprodu...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature03629
更新日期:2005-07-14 00:00:00
abstract::We are facing a global metabolic health crisis provoked by an obesity epidemic. Here we report the human gut microbial composition in a population sample of 123 non-obese and 169 obese Danish individuals. We find two groups of individuals that differ by the number of gut microbial genes and thus gut bacterial richness...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature12506
更新日期:2013-08-29 00:00:00
abstract::Ageing is a result of gradual and overall functional deteriorations across the body; however, it is unknown whether an individual tissue primarily works to mediate the ageing progress and control lifespan. Here we show that the hypothalamus is important for the development of whole-body ageing in mice, and that the un...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature12143
更新日期:2013-05-09 00:00:00
abstract::The signature of Dansgaard-Oeschger events--millennial-scale abrupt climate oscillations during the last glacial period--is well established in ice cores and marine records. But the effects of such events in continental settings are not as clear, and their absolute chronology is uncertain beyond the limit of (14)C dat...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature01391
更新日期:2003-02-20 00:00:00
abstract::Rapidly growing cells produce thousands of new ribosomes each minute, in a tightly regulated process that is essential to cell growth. How the Escherichia coli 16S ribosomal RNA and the 20 proteins that make up the 30S ribosomal subunit can assemble correctly in a few minutes remains a challenging problem, partly beca...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature07298
更新日期:2008-10-30 00:00:00
abstract::A timescale is necessary for estimating rates of molecular and morphological change in organisms and for interpreting patterns of macroevolution and biogeography. Traditionally, these times have been obtained from the fossil record, where the earliest representatives of two lineages establish a minimum time of diverge...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/31927
更新日期:1998-04-30 00:00:00
abstract::Protonic ceramic fuel cells, like their higher-temperature solid-oxide fuel cell counterparts, can directly use both hydrogen and hydrocarbon fuels to produce electricity at potentially more than 50 per cent efficiency1,2. Most previous direct-hydrocarbon fuel cell research has focused on solid-oxide fuel cells based ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/s41586-018-0082-6
更新日期:2018-05-01 00:00:00
abstract::Neuronal circuits across several systems display remarkable plasticity to sensory input during postnatal development. Experience-dependent refinements are often restricted to well-defined critical periods in early life, but how these are established remains mostly unknown. A representative example is the loss of respo...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/35004582
更新日期:2000-03-09 00:00:00
abstract::Spin dynamics in antiferromagnets has much shorter timescales than in ferromagnets, offering attractive properties for potential applications in ultrafast devices1-3. However, spin-current generation via antiferromagnetic resonance and simultaneous electrical detection by the inverse spin Hall effect in heavy metals h...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/s41586-020-1950-4
更新日期:2020-02-01 00:00:00
abstract::A major effect of insulin is to increase glucose transport in muscle and fat. A family of genes encoding distinct mammalian glucose transporters has recently been elucidated. One of these, the insulin-regulatable glucose transporter (IRGT), is primarily expressed in muscle and fat, tissues that exhibit insulin-depende...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/346369a0
更新日期:1990-07-26 00:00:00
abstract::Sea ice and dust flux increased greatly in the Southern Ocean during the last glacial period. Palaeorecords provide contradictory evidence about marine productivity in this region, but beyond one glacial cycle, data were sparse. Here we present continuous chemical proxy data spanning the last eight glacial cycles (740...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature04614
更新日期:2006-03-23 00:00:00
abstract::Cytotoxic T cells lyse only those virus infected target cells in vitro which express, in addition to the viral antigen(s), those K or D region products of the major histocompatibility complex (MHC) which were present during anti-viral sensitisation in vivo. This 'associative recognition' by cytotoxic T cells could ref...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/267160a0
更新日期:1977-05-12 00:00:00
abstract::Chemotaxis in Caenorhabditis elegans, like chemotaxis in bacteria, involves a random walk biased by the time derivative of attractant concentration, but how the derivative is computed is unknown. Laser ablations have shown that the strongest deficits in chemotaxis to salts are obtained when the ASE chemosensory neuron...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature06927
更新日期:2008-07-03 00:00:00
abstract::Different classes of retroviruses have been shown to induce immunodeficiency diseases in various animal species. These animal models may provide an insight into our understanding of AIDS but, with the exception of one strain of feline leukaemia virus, the determinants of pathogenicity have not yet been mapped to these...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/338505a0
更新日期:1989-04-06 00:00:00
abstract::In vitro mutagenesis of sequences required for the self-catalysed cleavage of a plant virus satellite RNA has allowed definition of an RNA segment with endoribonuclease activity. General rules have been deduced for the design of new RNA enzymes capable of highly specific RNA cleavage, and have been successfully tested...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/334585a0
更新日期:1988-08-18 00:00:00
abstract::The protein HLA-E is a non-classical major histocompatibility complex (MHC) molecule of limited sequence variability. Its expression on the cell surface is regulated by the binding of peptides derived from the signal sequence of some other MHC class I molecules. Here we report the identification of ligands for HLA-E. ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/35869
更新日期:1998-02-19 00:00:00
abstract::The requirement of metabolic energy for the interaction of polyene macrolide antibiotics with eukaryotic organisms remains a controversial subject (for review see ref. 1) It has been claimed that the lethal binding of these antibiotics to the sterol target component of the hydrophobic core of the membrane, in accordan...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/281080a0
更新日期:1979-09-06 00:00:00
abstract::Although stars form from clouds of gas and dust, there are insignificant amounts of gas around ordinary (Sun-like) stars. This suggests that hydrogen and helium, the primary constituents of planets such as Jupiter and Saturn, are not easily retained in orbit as a star matures. The gas-giant planets in the Solar System...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/373494a0
更新日期:1995-02-09 00:00:00
abstract::The widely occurring tetradecapeptide somatostatin (SRIF-14) has been variously implicated as a neurotransmitter, a neurohormone, a cybernin (local regulatory factor) and a hormone. In the first isolation of SRIF-14 from hypothalamic extracts and subsequent extracts of other tissues, peptides of higher molecular weigh...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/291076a0
更新日期:1981-05-07 00:00:00
abstract::Skeletal muscles consist of motor units which may differ considerably in contractile properties and types of usage. Some units participate mainly in relatively rare, quick movements and contract rapidly and are easily fatigued (type FF); others contribute to the maintenance of posture and hence contract slowly and are...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/314164a0
更新日期:1985-03-14 00:00:00
abstract::In vitro studies of muscle mitochondrial metabolism in patients with mitochondrial myopathy have identified a variety of functional defects of the mitochondrial respiratory chain, predominantly affecting complex I (NADH-CoQ reductase) or complex III (ubiquinol-cytochrome c reductase) in adult cases. These two enzymes ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/331717a0
更新日期:1988-02-25 00:00:00
abstract::One of us has previously reported that treatment of the Keilin and Hartree heart-muscle preparation with 2,3-dimercaptopropanol (BAL), in the presence of air, leads to the complete inactivation of the succinate oxidase system with little if any effect on the activities of succinate dehydrogenase (until more than half ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/288717a0
更新日期:1980-12-25 00:00:00