Showing papers in "Physical Review Letters in 2011"
TL;DR: It is demonstrated that silicene with topologically nontrivial electronic structures can realize the quantum spin Hall effect (QSHE) by exploiting adiabatic continuity and the direct calculation of the Z(2) topological invariant.
Abstract: We investigate the spin-orbit opened energy gap and the band topology in recently synthesized silicene as well as two-dimensional low-buckled honeycomb structures of germanium using first-principles calculations. We demonstrate that silicene with topologically nontrivial electronic structures can realize the quantum spin Hall effect (QSHE) by exploiting adiabatic continuity and the direct calculation of the Z(2) topological invariant. We predict that the QSHE can be observed in an experimentally accessible low temperature regime in silicene with the spin-orbit band gap of 1.55 meV, much higher than that of graphene. Furthermore, we find that the gap will increase to 2.9 meV under certain pressure strain. Finally, we also study germanium with a similar low-buckled stable structure, and predict that spin-orbit coupling opens a band gap of 23.9 meV, much higher than the liquid nitrogen temperature.
1,940 citations
TL;DR: Four-dimensional covariant nonlinear theories of massive gravity are constructed which are ghost-free in the decoupling limit to all orders, and the Hamiltonian constraint is maintained at least up to and including quartic order in nonlinearities, hence excluding the possibility of the Boulware-Deser ghost up to this order.
Abstract: We construct four-dimensional covariant nonlinear theories of massive gravity which are ghost-free in the decoupling limit to all orders. These theories resum explicitly all the nonlinear terms of an effective field theory of massive gravity. We show that away from the decoupling limit the Hamiltonian constraint is maintained at least up to and including quartic order in nonlinearities, hence excluding the possibility of the Boulware-Deser ghost up to this order. We also show that the same remains true to all orders in a similar toy model.
1,909 citations
TL;DR: In this paper, a simple realization of the 3D Weyl semimetal phase was proposed, utilizing a multilayer structure, composed of identical thin films of a magnetically doped 3D topological insulator, separated by ordinary-insulator spacer layers.
Abstract: We propose a simple realization of the three-dimensional (3D) Weyl semimetal phase, utilizing a multilayer structure, composed of identical thin films of a magnetically doped 3D topological insulator, separated by ordinary-insulator spacer layers. We show that the phase diagram of this system contains a Weyl semimetal phase of the simplest possible kind, with only two Dirac nodes of opposite chirality, separated in momentum space, in its band structure. This Weyl semimetal has a finite anomalous Hall conductivity and chiral edge states and occurs as an intermediate phase between an ordinary insulator and a 3D quantum anomalous Hall insulator. We find that the Weyl semimetal has a nonzero dc conductivity at zero temperature, but Drude weight vanishing as ${T}^{2}$, and is thus an unusual metallic phase, characterized by a finite anomalous Hall conductivity and topologically protected edge states.
1,803 citations
TL;DR: Parity-time (PT) symmetric periodic structures, near the spontaneous PT-symmetry breaking point, can act as unidirectional invisible media and the transmission coefficient and phase are indistinguishable from those expected in the absence of a grating.
Abstract: Parity-time (PT) symmetric periodic structures, near the spontaneous PT-symmetry breaking point, can act as unidirectional invisible media. In this regime, the reflection from one end is diminished while it is enhanced from the other. Furthermore, the transmission coefficient and phase are indistinguishable from those expected in the absence of a grating. The phenomenon is robust even in the presence of Kerr nonlinearities, and it can also effectively suppress optical bistabilities.
1,656 citations
TL;DR: A class of three-dimensional "topological crystalline insulators" which have metallic surface states with quadratic band degeneracy on high symmetry crystal surfaces is found.
Abstract: The recent discovery of topological insulators has revived interest in the band topology of insulators. In this Letter, we extend the topological classification of band structures to include certain crystal point group symmetry. We find a class of three-dimensional ``topological crystalline insulators'' which have metallic surface states with quadratic band degeneracy on high symmetry crystal surfaces. These topological crystalline insulators are the counterpart of topological insulators in materials without spin-orbit coupling. Their band structures are characterized by new topological invariants. We hope this work will enlarge the family of topological phases in band insulators and stimulate the search for them in real materials.
1,641 citations
TL;DR: In this article, the spin Hall effect in a thin film with strong spin-orbit scattering can excite magnetic precession in an adjacent ferromagnetic film, and the ratio of these two signals allows a quantitative determination of the spin current and spin Hall angle.
Abstract: We demonstrate that the spin Hall effect in a thin film with strong spin-orbit scattering can excite magnetic precession in an adjacent ferromagnetic film. The flow of alternating current through a Pt/NiFe bilayer generates an oscillating transverse spin current in the Pt, and the resultant transfer of spin angular momentum to the NiFe induces ferromagnetic resonance dynamics. The Oersted field from the current also generates a ferromagnetic resonance signal but with a different symmetry. The ratio of these two signals allows a quantitative determination of the spin current and the spin Hall angle.
1,421 citations
TL;DR: The T2K experiment observes indications of ν (μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target, and under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance.
Abstract: The T2K experiment observes indications of nu(mu) -> nu(mu) e appearance in data accumulated with 1.43 x 10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Delta m(23)(2)| = 2.4 x 10(-3) eV(2), sin(2)2 theta(23) = 1 and sin(2)2 theta(13) = 0, the expected number of such events is 1.5 +/- 0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7 x 10(-3), equivalent to 2.5 sigma significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2 theta(13) < 0.28(0.34) for delta(CP) = 0 and a normal (inverted) hierarchy.
1,361 citations
TL;DR: This Letter demonstrates, for the first time, selective thermal emitters based on metamaterial perfect absorbers and finds that emissivity and absorptivity agree very well as predicted by Kirchhoff's law of thermal radiation.
Abstract: In this Letter we demonstrate, for the first time, selective thermal emitters based on metamaterial perfect absorbers. We experimentally realize a narrow band midinfrared (MIR) thermal emitter. Multiple metamaterial sublattices further permit construction of a dual-band MIR emitter. By performing both emissivity and absorptivity measurements, we find that emissivity and absorptivity agree very well as predicted by Kirchhoff's law of thermal radiation. Our results directly demonstrate the great flexibility of metamaterials for tailoring blackbody emission.
1,305 citations
TL;DR: In this paper, it was shown that the quantum Hall effect without an external magnetic field can be achieved in a known ferromagnetic compound HgCr2Se4, with a single pair of Weyl fermions separated in momentum space.
Abstract: In 3D momentum space, a topological phase boundary separating the Chern insulating layers from normal insulating layers may exist, where the gap must be closed, resulting in a "Chern semimetal" state with topologically unavoidable band crossings at the Fermi level. This state is a condensed-matter realization of Weyl fermions in (3+1)D, and should exhibit remarkable features, such as magnetic monopoles and Fermi arcs. Here we predict, based on first principles calculations, that such a novel quantum state can be realized in a known ferromagnetic compound HgCr2Se4, with a single pair of Weyl fermions separated in momentum space. The quantum Hall effect without an external magnetic field can be achieved in its quantum-well structure.
1,162 citations
TL;DR: A new architecture for superconducting quantum circuits employing a three-dimensional resonator that suppresses qubit decoherence while maintaining sufficient coupling to the control signal is introduced, demonstrating that Josephson junction qubits are highly coherent.
Abstract: Superconducting quantum circuits based on Josephson junctions have made rapid progress in demonstrating quantum behavior and scalability. However, the future prospects ultimately depend upon the intrinsic coherence of Josephson junctions, and whether superconducting qubits can be adequately isolated from their environment. We introduce a new architecture for superconducting quantum circuits employing a three-dimensional resonator that suppresses qubit decoherence while maintaining sufficient coupling to the control signal. With the new architecture, we demonstrate that Josephson junction qubits are highly coherent, with ${T}_{2}\ensuremath{\sim}10$ to $20\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ without the use of spin echo, and highly stable, showing no evidence for $1/f$ critical current noise. These results suggest that the overall quality of Josephson junctions in these qubits will allow error rates of a few ${10}^{\ensuremath{-}4}$, approaching the error correction threshold.
1,074 citations
TL;DR: In this paper, the authors reported the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits by investigating the coherence of up to 8 ions over time and observed a decay proportional to the square of the number of qubits.
Abstract: We report the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits. By investigating the coherence of up to 8 ions over time, we observe a decay proportional to the square of the number of qubits. The observed decay agrees with a theoretical model which assumes a system affected by correlated, Gaussian phase noise. This model holds for the majority of current experimental systems developed towards quantum computation and quantum metrology.
TL;DR: Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect and an irreducible excess of bulklike events below 3 keV in ionization energy are discussed.
Abstract: We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss an irreducible excess of bulklike events below 3 keV in ionization energy. These could be caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible to determine their origin. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.
TL;DR: This work presents the first experimental results with observations of the Peregrine soliton in a water wave tank, and proposes a new approach to modeling deep water waves using the nonlinear Schrödinger equation.
Abstract: The conventional definition of rogue waves in the ocean is that their heights, from crest to trough, are more than about twice the significant wave height, which is the average wave height of the largest one-third of nearby waves. When modeling deep water waves using the nonlinear Schr\"odinger equation, the most likely candidate satisfying this criterion is the so-called Peregrine solution. It is localized in both space and time, thus describing a unique wave event. Until now, experiments specifically designed for observation of breather states in the evolution of deep water waves have never been made in this double limit. In the present work, we present the first experimental results with observations of the Peregrine soliton in a water wave tank.
TL;DR: Gravity Probe B, launched 20 April 2004, is a space experiment testing two fundamental predictions of Einstein's theory of general relativity, the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit, results in a geodetically drift rate of -6601.8±18.3 mas/yr.
Abstract: Gravity Probe B, launched 20 April 2004, is a space experiment testing two fundamental predictions of Einstein's theory of general relativity (GR), the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit. Data collection started 28 August 2004 and ended 14 August 2005. Analysis of the data from all four gyroscopes results in a geodetic drift rate of $\ensuremath{-}6601.8\ifmmode\pm\else\textpm\fi{}18.3\text{ }\text{ }\mathrm{mas}/\mathrm{yr}$ and a frame-dragging drift rate of $\ensuremath{-}37.2\ifmmode\pm\else\textpm\fi{}7.2\text{ }\text{ }\mathrm{mas}/\mathrm{yr}$, to be compared with the GR predictions of $\ensuremath{-}6606.1\text{ }\text{ }\mathrm{mas}/\mathrm{yr}$ and $\ensuremath{-}39.2\text{ }\text{ }\mathrm{mas}/\mathrm{yr}$, respectively (``mas'' is milliarcsecond; $1\text{ }\text{ }\mathrm{mas}=4.848\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}\text{ }\text{ }\mathrm{rad}$).
TL;DR: Using a scattering matrix formalism, the general scattering properties of optical structures that are symmetric under a combination of parity and time reversal (PT) are derived and a transition between PT-symmetric scattering eigenstates, which are norm preserving, and symmetry-broken pairs of eigenstate exhibiting net amplification and loss is demonstrated.
Abstract: Using a scattering matrix formalism, we derive the general scattering properties of optical structures that are symmetric under a combination of parity and time reversal (PT). We demonstrate the existence of a transition between PT-symmetric scattering eigenstates, which are norm preserving, and symmetry-broken pairs of eigenstates exhibiting net amplification and loss. The system proposed by Longhi [Phys. Rev. A 82, 031801 (2010).], which can act simultaneously as a laser and coherent perfect absorber, occurs at discrete points in the broken-symmetry phase, when a pole and zero of the S matrix coincide.
TL;DR: In this paper, a simple Landau-Ginzburg-type continuum theory of solvent-free ionic liquids is used to predict the structure of the electrical double layer.
Abstract: We develop a simple Landau-Ginzburg-type continuum theory of solvent-free ionic liquids and use it to predict the structure of the electrical double layer. The model captures overscreening from short-range correlations, dominant at small voltages, and steric constraints of finite ion sizes, which prevail at large voltages. Increasing the voltage gradually suppresses overscreening in favor of the crowding of counterions in a condensed inner layer near the electrode. This prediction, the ion profiles, and the capacitance-voltage dependence are consistent with recent computer simulations and experiments on room-temperature ionic liquids, using a correlation length of order the ion size.
Columbia University1, University of California, Los Angeles2, University of Zurich3, University of Münster4, University of Coimbra5, University of Nantes6, Weizmann Institute of Science7, University of Mainz8, Shanghai Jiao Tong University9, Max Planck Society10, Rice University11, University of Bologna12
TL;DR: The XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy, finds no evidence for dark matter, leading to the most stringent limit on dark matter interactions today.
Abstract: We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8{+-}0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0x10{sup -45} cm{sup 2} for a WIMP mass of 50 GeV/c{sup 2} at 90% confidence level.
TL;DR: The experiment clearly shows that the acoustic cloak can effectively bend the ultrasound waves around the hidden object, with reduced scattering and shadow, and indicates that this design approach should be scalable to different acoustic frequencies and offers the possibility for a variety of devices based on coordinate transformation.
Abstract: Invisibility devices based on coordinate transformation have opened up a new field of considerable interest. We present here the first practical realization of a low-loss and broadband acoustic cloak for underwater ultrasound. This metamaterial cloak is constructed with a network of acoustic circuit elements, namely, serial inductors and shunt capacitors. Our experiment clearly shows that the acoustic cloak can effectively bend the ultrasound waves around the hidden object, with reduced scattering and shadow. Because of the nonresonant nature of the building elements, this low-loss (� 6d B=m) cylindrical cloak exhibits invisibility over a broad frequency range from 52 to 64 kHz. Furthermore, our experimental study indicates that this design approach should be scalable to different acoustic frequencies and offers the possibility for a variety of devices based on coordinate transformation.
TL;DR: This analysis shows strong evidence for the existence of helical edge modes proposed by Liu et al, which persist in spite of sizable bulk conduction and show only a weak magnetic field dependence.
Abstract: We present an experimental study of low temperature electronic transport in the hybridization gap of inverted InAs/GaSb composite quantum wells. An electrostatic gate is used to push the Fermi level into the gap regime, where the conductance as a function of sample length and width is measured. Our analysis shows strong evidence for the existence of helical edge modes proposed by Liu et al [Phys. Rev. Lett. 100, 236601 (2008)]. Edge modes persist in spite of sizable bulk conduction and show only a weak magnetic field dependence-a direct consequence of a gap opening away from the zone center.
TL;DR: Dense suspension and granular media are unified under a common framework and the results are shown to be compatible with classical empirical models of suspension rheology and provide a clear determination of constitutive laws close to the jamming transition.
Abstract: Using an original pressure-imposed shear cell, we study the rheology of dense suspensions. We show that they exhibit a viscoplastic behavior similarly to granular media successfully described by a frictional rheology and fully characterized by the evolution of the friction coefficient μ and the volume fraction ϕ with a dimensionless viscous number I(v). Dense suspension and granular media are thus unified under a common framework. These results are shown to be compatible with classical empirical models of suspension rheology and provide a clear determination of constitutive laws close to the jamming transition.
Fermilab1, University of Sussex2, Argonne National Laboratory3, University of Oxford4, University of Minnesota5, Brookhaven National Laboratory6, University of Cambridge7, University of Texas at Austin8, Harvard University9, Tufts University10, State University of Campinas11, Indiana University12, University of Pittsburgh13, University College London14, College of the Holy Cross15, Universidade Federal de Goiás16, University of São Paulo17, Illinois Institute of Technology18, University of Warsaw19, California Institute of Technology20, Stanford University21
TL;DR: The results of a search for ν(e) appearance in a ν (μ) beam in the MINOS long-baseline neutrino experiment find that 2 sin(2) (θ(23))sin(2)(2θ (13))<0.12 at 90% confidence level for δ = 0 and the normal (inverted) neutrinos mass hierarchy.
Abstract: We report the results of a search for ν(e) appearance in a ν(μ) beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 × 10(20) protons on the NuMI target at Fermilab, we find that 2 sin(2) (θ(23))sin(2)(2θ(13))<0.12(0.20) at 90% confidence level for δ = 0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin(2) (θ(23))sin(2)(2θ(13)) = 0.041(-0.031)(+0.047) (0.079(-0.053) (+0.071)). The θ(13) = 0 hypothesis is disfavored by the MINOS data at the 89% confidence level.
TL;DR: A criterion for quantum integrability is proposed which shows that the Rabi model is integrable due to the presence of a discrete symmetry; a generalization with no symmetries is introduced, which is the first example of a nonintegrable but exactly solvable system.
Abstract: The Rabi model is a paradigm for interacting quantum systems. It couples a bosonic mode to the smallest possible quantum model, a two-level system. I present the analytical solution which allows us to consider the question of integrability for quantum systems that do not possess a classical limit. A criterion for quantum integrability is proposed which shows that the Rabi model is integrable due to the presence of a discrete symmetry. Moreover, I introduce a generalization with no symmetries; the generalized Rabi model is the first example of a nonintegrable but exactly solvable system.
TL;DR: This work creates an sp2-hybridized one-atom-thick flat carbon membrane with a random arrangement of polygons, including four-membered carbon rings that possess a band gap, which may open new possibilities for engineering graphene-based electronic devices.
Abstract: While crystalline two-dimensional materials have become an experimental reality during the past few years, an amorphous 2D material has not been reported before. Here, using electron irradiation we create an $s{p}^{2}$-hybridized one-atom-thick flat carbon membrane with a random arrangement of polygons, including four-membered carbon rings. We show how the transformation occurs step by step by nucleation and growth of low-energy multivacancy structures constructed of rotated hexagons and other polygons. Our observations, along with first-principles calculations, provide new insights to the bonding behavior of carbon and dynamics of defects in graphene. The created domains possess a band gap, which may open new possibilities for engineering graphene-based electronic devices.
TL;DR: It is proved that the protocol provides an efficient and reliable estimate of the average error-rate for a set operations (gates) under a very general noise model that allows for both time and gate-dependent errors.
Abstract: In this Letter we propose a fully scalable randomized benchmarking protocol for quantum information processors. We prove that the protocol provides an efficient and reliable estimate of the average error-rate for a set operations (gates) under a very general noise model that allows for both time and gate-dependent errors. In particular we obtain a sequence of fitting models for the observable fidelity decay as a function of a (convergent) perturbative expansion of the gate errors about the mean error. We illustrate the protocol through numerical examples.
TL;DR: The Bose-Einstein condensation (BEC) of the most magnetic element, dysprosium is reported and it is observed that stable BEC formation depends on the relative angle of a small polarizing magnetic field to the axis of the oblate trap, a property of trapped condensates only expected in the strongly dipolar regime.
Abstract: We report the Bose-Einstein condensation (BEC) of the most magnetic element, dysprosium. The Dy BEC is the first for an open f-shell lanthanide (rare-earth) element and is produced via forced evaporation in a crossed optical dipole trap loaded by an unusual, blue-detuned and spin-polarized narrowline magneto-optical trap. Nearly pure condensates of 1.5 × 10(4) (164)Dy atoms form below T = 30 nK. We observe that stable BEC formation depends on the relative angle of a small polarizing magnetic field to the axis of the oblate trap, a property of trapped condensates only expected in the strongly dipolar regime. This regime was heretofore only attainable in Cr BECs via a Feshbach resonance accessed at a high-magnetic field.
TL;DR: A higher-order Poincaré sphere and Stokes parameter representation of the higher- order states of polarization of vector vortex beams that includes radial and azimuthal polarized cylindrical vector beams is presented.
Abstract: A higher-order Poincare sphere and Stokes parameter representation of the higher-order states of polarization of vector vortex beams that includes radial and azimuthal polarized cylindrical vector beams is presented. The higher-order Poincare sphere is constructed by naturally extending the Jones vector basis of plane wave polarization in terms of optical spin angular momentum to the total optical angular momentum that includes higher dimensional orbital angular momentum. The salient properties of this representation are illustrated by its ability to describe the higher-order modes of optical fiber waveguides, more exotic vector beams, and a higher-order Pancharatnam-Berry geometric phase.
TL;DR: A simple prescription to flatten isolated Bloch bands with a nonzero Chern number is presented and perfect flattening can be attained with further range hoppings that decrease exponentially with distance.
Abstract: We present a simple prescription to flatten isolated Bloch bands with a nonzero Chern number. We first show that approximate flattening of bands with a nonzero Chern number is possible by tuning ratios of nearest-neighbor and next-nearest-neighbor hoppings in the Haldane model and, similarly, in the chiral-$\ensuremath{\pi}$-flux square lattice model. Then we show that perfect flattening can be attained with further range hoppings that decrease exponentially with distance. Finally, we add interactions to the model and present exact diagonalization results for a small system at $1/3$ filling that support (i) the existence of a spectral gap, (ii) that the ground state is a topological state, and (iii) that the Hall conductance is quantized.
TL;DR: In this paper, the authors considered the time evolution of observables in the transverse-field Ising chain after a sudden quench of the magnetic field and provided exact analytical results for the asymptotic time and distance dependence of one-and two-point correlation functions of the order parameter.
Abstract: We consider the time evolution of observables in the transverse-field Ising chain after a sudden quench of the magnetic field. We provide exact analytical results for the asymptotic time and distance dependence of one- and two-point correlation functions of the order parameter. We employ two complementary approaches based on asymptotic evaluations of determinants and form-factor sums. We prove that the stationary value of the two-point correlation function is not thermal, but can be described by a generalized Gibbs ensemble (GGE). The approach to the stationary state can also be understood in terms of a GGE. We present a conjecture on how these results generalize to particular quenches in other integrable models.
TL;DR: This work presents a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope, and is able to rule out models with the most generic cross section, using gamma rays.
Abstract: Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particl ...
TL;DR: In this article, the authors used Raman-assisted tunneling in an optical superlattice to generate large tunable effective magnetic fields for ultracold atoms, where the accumulated phase shift by an atom is equivalent to the Aharonov-Bohm phase of a charged particle exposed to a staggered magnetic field of large magnitude.
Abstract: We use Raman-assisted tunneling in an optical superlattice to generate large tunable effective magnetic fields for ultracold atoms. When hopping in the lattice, the accumulated phase shift by an atom is equivalent to the Aharonov-Bohm phase of a charged particle exposed to a staggered magnetic field of large magnitude, on the order of 1 flux quantum per plaquette. We study the ground state of this system and observe that the frustration induced by the magnetic field can lead to a degenerate ground state for noninteracting particles. We provide a measurement of the local phase acquired from Raman-induced tunneling, demonstrating time-reversal symmetry breaking of the underlying Hamiltonian. Furthermore, the quantum cyclotron orbit of single atoms in the lattice exposed to the magnetic field is directly revealed.