Accelerating electrons to relativistic energies has applications in time-resolved electron diffraction. Experiments and simulations show that inhomogeneities in a laser’s electric field affect the quality of the accelerated electron beam.

[Phys. Rev. X 5, 031012] Published Fri Jul 31, 2015

]]>Weyl fermions possess exotic properties and can act like magnetic monopoles. Researchers show that TaAs is a Weyl semimetal, demonstrating for the first time that Weyl semimetals can be identified experimentally.

[Phys. Rev. X 5, 031013] Published Fri Jul 31, 2015

]]>In everyday life, if sound propagates from one location to another, it can propagate backwards just as easily. However, theorists show that it is possible to harness the radiation pressure interaction between light and matter to produce unidirectional sound propagation.

[Phys. Rev. X 5, 031011] Published Tue Jul 28, 2015

]]>Quantum effects are very sensitive to noise, which is a fundamental limit in all experiments. Researchers show that they nevertheless enable precise measurements of magnetic fields in a noisy environment.

[Phys. Rev. X 5, 031010] Published Wed Jul 22, 2015

]]>Quantum networks built out of distinct quantum bits (qubits) connected via photons may enable quantum computation and long-distance communication. The high yield integration of high-quality solid-state qubits into an on-chip photonic circuit could provide a stable and scalable architecture to build such a network.

[Phys. Rev. X 5, 031009] Published Tue Jul 21, 2015

]]>Researchers show that electronic systems with a common type of magnetic order form a new glassy state of matter due to imperfections. In this phase, the spins of the electrons are randomly aligned or anti-aligned with a spontaneously chosen axis.

[Phys. Rev. X 5, 031008] Published Mon Jul 20, 2015

]]>With the assistance of lattice vibrations, quantum dots perform as single-photon emitters.

[Phys. Rev. X 5, 031006] Published Thu Jul 16, 2015

]]>Quantum phase transitions, which are driven by a parameter in the Hamiltonian, can be thought as certain classical phase transitions in the modern formulation of quantum Monte Carlo methods. A new generic tool captures quantum phase transitions in a simple and efficient manner.

[Phys. Rev. X 5, 031007] Published Wed Jul 15, 2015

]]>An array of helical elements absorbs radiation of a certain frequency while casting no shadow in light over a range of other frequencies.

[Phys. Rev. X 5, 031005] Published Tue Jul 14, 2015

]]>Optical imaging resolution is ultimately limited by light’s quantum noise, which is manifested by small quantum fluctuations in its electric field. A new technique allows these correlations to be controlled simultaneously at all points in space and has the potential to yield smoother images.

[Phys. Rev. X 5, 031004] Published Thu Jul 09, 2015

]]>Polariton condensates can store bits of information and are characterized by long lifetimes. Researchers experimentally show how a polariton condensate acts as an optical spin memory that can be rapidly flipped.

[Phys. Rev. X 5, 031002] Published Wed Jul 08, 2015

]]>In active liquid crystals, turbulence can occur in the absence of external forces due to internal active stresses. Researchers show that the geometrical structure of such a turbulent flow is strongly correlated with the presence of topological defects in the liquid crystal.

[Phys. Rev. X 5, 031003] Published Wed Jul 08, 2015

]]>Quasiparticles dubbed topological polaritons make their debut in the theoretical world.

[Phys. Rev. X 5, 031001] Published Wed Jul 01, 2015

]]>The interaction of light and matter is fundamental in physics. New results show that quantum coherence can arise in a cavity containing multiple modes of light and an artificial atom.

[Phys. Rev. X 5, 021035] Published Mon Jun 29, 2015

]]>New sources and detectors allow atomic and molecular structure to be studied at mid-infrared wavelengths, where interpreting experiments is more straightforward.

[Phys. Rev. X 5, 021034] Published Fri Jun 26, 2015

]]>Water is an abundant resource on Earth and at low temperatures it occurs in hexagonal and cubic forms that differ only in molecular arrangements. Researchers use quantum-mechanical simulations to explain why hexagonal ice has a lower overall free energy than the cubic form and thus why snowflakes are hexagonal.

[Phys. Rev. X 5, 021033] Published Wed Jun 24, 2015

]]>Ferromagnetism of delocalized fermions is a fundamental aspect of condensed-matter physics but is difficult to describe using typical perturbative methods. Using nonperturbative simulations, scientists accurately determine the ferromagnetic transition temperature and other thermodynamic properties of a ferromagnetic metal.

[Phys. Rev. X 5, 021032] Published Tue Jun 23, 2015

]]>Porous metamaterials exhibit dramatic changes in their Hall voltage relative to their bulk material. Researchers theoretically investigate this result and suggest techniques for experimental verification.

[Phys. Rev. X 5, 021030] Published Mon Jun 22, 2015

]]>The surface states of topological insulators are protected from backscattering, making them a promising resource for computing and materials science. This topological protection is now demonstrated in a radio-frequency circuit.

[Phys. Rev. X 5, 021031] Published Mon Jun 22, 2015

]]>[Phys. Rev. X 5, 029902] Published Mon Jun 22, 2015

]]>Understanding memory and decision making in the human brain requires generating models of how neurons fire. Using ordinary differential equations, researchers formulate an exact firing rate description for an ensemble of spiking neurons.

[Phys. Rev. X 5, 021028] Published Fri Jun 19, 2015

]]>Topological insulators consist of electrons that are either free or weakly interacting, which makes such systems computationally tractable. A new study describes topological insulators of bosons—a strongly correlated problem—and shows that their low-energy physics is captured by an exotic theory.

[Phys. Rev. X 5, 021029] Published Fri Jun 19, 2015

]]>Ions with multiple quantum states are useful test beds for quantum magnetism and memory. Researchers use trapped ${}^{171}$Yb ions to control interactions among ions with three quantum states.

[Phys. Rev. X 5, 021026] Published Wed Jun 17, 2015

]]>Quantum simulations are expected to vastly outperform classical simulations when modeling the dynamics of interacting spin systems. A digital quantum simulation shows that spin dynamics can be studied and predicted, laying the groundwork for applications in quantum magnetism.

[Phys. Rev. X 5, 021027] Published Wed Jun 17, 2015

]]>Nonreciprocal photonic systems allow for the unidirectional transmission and amplification of photons, which enables a host of applications. A new and general approach for realizing nonreciprocal interactions shows how they can be used to construct quantum-limited amplifiers and isolators.

[Phys. Rev. X 5, 021025] Published Mon Jun 15, 2015

]]>Power generation from nuclear fusion requires that highly energetic plasmas be stably confined. New evidence shows how high plasma pressures help to confine high-energy electrons in a stable magnetic cusp, laying the groundwork for efficient fusion reactors.

[Phys. Rev. X 5, 021024] Published Thu Jun 11, 2015

]]>For quantum computing to be practical, the effects of decoherence on quantum information must be minimized. Discovery of a regime in which transitions that conserve parity are much more likely to occur than those that do not opens the door to parity-based information processing proposals to protect quantum information.

[Phys. Rev. X 5, 021023] Published Wed Jun 10, 2015

]]>Bismuth is known for its extremely mobile electrons whose capacity to conduct electricity is drastically diminished in the presence of magnetic fields. A new study shows how the orbital magnetoresistance changes as a function of both temperature and magnetic field strength.

[Phys. Rev. X 5, 021022] Published Tue Jun 09, 2015

]]>Some materials exhibit ground states that are disordered, even in the zero-temperature limit. Researchers derive theoretical relations of thermodynamic and structural properties to describe these unexpected states.

[Phys. Rev. X 5, 021020] Published Fri May 29, 2015

]]>Electromagnetic scattering has applications in astrophysics, atmospheric science, and medical imaging. Researchers design a metamaterial that exhibits anomalously weak scattering over a band of optical frequencies.

[Phys. Rev. X 5, 021021] Published Fri May 29, 2015

]]>A general framework already exists to describe how insulators respond to electromagnetic fields. Now, a new universal framework describes the response of both insulators and metals.

[Phys. Rev. X 5, 021018] Published Tue May 26, 2015

]]>Combining the qualities of superconductors and ferromagnets allows for the creation of new superconducting electronics. Cooper pairs in superconductors—which do not possess spin—can be altered to have spin using a special ferromagnet.

[Phys. Rev. X 5, 021019] Published Tue May 26, 2015

]]>Strongly interacting topological phases constitute a recent field of condensed-matter physics. An investigation of a model of a topological insulator with exotic magnetic edge states helps explain how these states emerge.

[Phys. Rev. X 5, 021017] Published Fri May 22, 2015

]]>Although transition-metal oxides usually lack the combination of suitable band gaps and carrier transport properties desired for solar energy applications, such semiconducting properties can be realized in metastable MnO-ZnO alloys.

[Phys. Rev. X 5, 021016] Published Mon May 18, 2015

]]>Topological defects can occur during the transition from disorder to order. Researchers quantitatively predict the formation rate of defects using scaling ideas, linear response, and insights from gravity.

[Phys. Rev. X 5, 021015] Published Thu May 14, 2015

]]>[Phys. Rev. X 5, 029901] Published Wed May 13, 2015

]]>A near-infrared microscopy technique can detect defects in electronic devices with a resolution better than the diffraction limit of light.

[Phys. Rev. X 5, 021014] Published Wed May 06, 2015

]]>Using basic building blocks to assemble colloids analogous to molecules may pave the way for developing new metamaterials. A new method allows different “molecule” shapes to be controlled using particle size ratio, charge ratio ion concentrations, and external electric fields.

[Phys. Rev. X 5, 021012] Published Wed Apr 29, 2015

]]>Superconductors hold great promise for allowing electrical current to flow unimpeded by resistance. A new study finds that an iron pnictide doped with copper possesses a local electronic structure strikingly similar to that of cuprate superconductors.

[Phys. Rev. X 5, 021013] Published Wed Apr 29, 2015

]]>Time measurements and navigation rely on atomic interferometers and atomic clocks. A new technique can improve the stability of such clocks by coupling a classical oscillator to an ensemble of atoms in a superposition state using repeated, coherence-preserving measurements.

[Phys. Rev. X 5, 021011] Published Mon Apr 27, 2015

]]>Using quantum systems to simulate the behavior of other quantum systems is a step toward achieving revolutionary computing. Entangled photons are used to simulate the eigenstates of spin systems and how they change when the external magnetic field and spin-coupling are altered.

[Phys. Rev. X 5, 021010] Published Fri Apr 24, 2015

]]>Identifying atomic nuclei using magnetic spins is done in many fields of biology and chemistry. A new investigation shows that the presence of harmonic signals can make it difficult to accurately identify a heterogeneous group of atoms.

[Phys. Rev. X 5, 021009] Published Wed Apr 22, 2015

]]>Hybrid nanostructures composed of both typical atoms and metallic nanoparticles such as nanoresonators host a variety of optical properties. Analytical modeling is used to derive the optical responses of such materials in a computationally feasible way.

[Phys. Rev. X 5, 021008] Published Fri Apr 17, 2015

]]>Doping Mott insulators to produce conductive materials has applications in transistors and switches. Researchers show how to calculate the critical doping needed to overcome the insulating behavior and produce a metal.

[Phys. Rev. X 5, 021007] Published Wed Apr 15, 2015

]]>Identifying groups of highly correlated units in a complex system is a notoriously challenging task. A new technique that adapts tools from network theory solves this problem and is used to map the mesoscopic structure of various stock markets.

[Phys. Rev. X 5, 021006] Published Tue Apr 14, 2015

]]>A new model can compute when a spreading disease triggers an epidemic within a network that varies with time.

[Phys. Rev. X 5, 021005] Published Wed Apr 08, 2015

]]>Quantum computation commonly relies on qubits, but rebits—states with real density matrices—can be used as well. Researchers show how the contextuality of two-level states is necessary for quantum computation.

[Phys. Rev. X 5, 021003] Published Thu Apr 02, 2015

]]>Quantized resistance—the fractional quantum Hall effect—was used to uncover the mysterious so-called 5/2 state. Theoretical modeling suggests that spin-polarized electrons in GaAs semiconductors defining this state host a fundamentally new type of quantum particle.

[Phys. Rev. X 5, 021004] Published Thu Apr 02, 2015

]]>Quantum mechanics and thermodynamics are fundamental fields of physics. Scientists show how the processing of quantum coherence is constrained by the laws of thermodynamics.

[Phys. Rev. X 5, 021001] Published Wed Apr 01, 2015

]]>Life as we know it is built around water. Molecular dynamics simulations show that energy in water molecules is largely transferred between molecules as opposed to within individual molecules.

[Phys. Rev. X 5, 021002] Published Wed Apr 01, 2015

]]>A theoretical study of electronic interactions in graphene shows that a transverse component of valley conductivity emerges, while the longitudinal component cancels.

[Phys. Rev. X 5, 011040] Published Tue Mar 31, 2015

]]>High-entropy alloys are a new class of materials that have been shown to be strong, ductile, and corrosion-resistant. Ensembles of viable alloys are systematically isolated using density-functional theory.

[Phys. Rev. X 5, 011041] Published Tue Mar 31, 2015

]]>Ultracold atomic gases allow scientists to study the out-of-equilibrium dynamics of many-particle systems. A computationally tractable formalism is used to model systems of cold atoms trapped in an optical lattice.

[Phys. Rev. X 5, 011038] Published Mon Mar 30, 2015

]]>Momentum and angular momentum are ubiquitous in wave physics. Calculations show that unusual transverse momentum and spin angular momentum, thus far only recorded in evanescent waves, can also be seen in interfering propagating waves, like laser beams.

[Phys. Rev. X 5, 011039] Published Mon Mar 30, 2015

]]>Many biological structures, from macromolecules to proteins, as well as a number of solid-state systems including ferroelectric and ferro nano- and microstructures, possess static toroidal shapes. A theoretical study shows that the dynamic toroidal dipoles constructed from ionic crystals can be used to engineer metamaterials to control how electromagnetic radiation is scattered and transmitted.

[Phys. Rev. X 5, 011036] Published Fri Mar 27, 2015

]]>Futuristic electronic devices may rely on optical and transport properties that are highly sensitive to magnetic and orbital order. Researchers show that a doped $4d$ transition-metal oxide exhibits local or global changes in spin-orbital order.

[Phys. Rev. X 5, 011037] Published Fri Mar 27, 2015

]]>A tenet of classical physics—Newton’s third law—can in fact be violated when the interacting particles are embedded in a nonequilibrium environment. Researchers present the statistical foundations of many-body systems with such interactions.

[Phys. Rev. X 5, 011035] Published Thu Mar 26, 2015

]]>[Phys. Rev. X 5, 019902] Published Thu Mar 26, 2015

]]>Modeling a network with too many parameters is likely to lead to overfitting. The minimum description length principle is used to reliably model networks and robustly differentiate models on the basis of confidence levels.

[Phys. Rev. X 5, 011033] Published Wed Mar 25, 2015

]]>Photons confined to a hexagonally shaped microcavity move in a polarization-dependent way, thus simulating a spin-orbit coupling common in materials.

[Phys. Rev. X 5, 011034] Published Wed Mar 25, 2015

]]>Crystalline arrangements in solids affect the properties of various substances, such as steel. Using colloidal microspheres in an electric field, scientists model the kinetics of crystalline transformations.

[Phys. Rev. X 5, 011030] Published Tue Mar 24, 2015

]]>The effects of climate change can be mitigated by developing alternative energy sources. An investigation shows how the performance of organic solar cells degrades for doping levels above $7\times {10}^{15}$ cm${}^{-3}$.

[Phys. Rev. X 5, 011032] Published Tue Mar 24, 2015

]]>Cavity polaritons—a mixture of microcavity photons and material excitations—can be used to develop new types of lasers based on Bose-Einstein condensates. A roadmap is proposed for building such lasers using intersubband transitions in semiconductor quantum wells, highlighting realistic design challenges such as the quality factors of resonators.

[Phys. Rev. X 5, 011031] Published Mon Mar 23, 2015

]]>So-called Weyl points can be thought of as magnetic monopoles in momentum space. Researchers show that certain transition-metal monophosphides are characterized by Weyl points.

[Phys. Rev. X 5, 011029] Published Tue Mar 17, 2015

]]>Kondo lattices belong to a new class of materials defying standard concepts of solid-state physics. Scientists investigate the electronic structure of a well-known Kondo lattice and find that the Fermi surface is stable over a wide range above and below its Kondo temperature.

[Phys. Rev. X 5, 011028] Published Thu Mar 12, 2015

]]>Ensembles of people, research ideas, and cells all represent complex interacting networks. Scientists use a community-detection method to trace the interconnectedness of networks.

[Phys. Rev. X 5, 011027] Published Fri Mar 06, 2015

]]>Researchers show that a quantum critical point can be reached in Sc${}_{3.1}$In, a weak itinerant magnet without local moments, using chemical doping with lutetium.

[Phys. Rev. X 5, 011026] Published Wed Mar 04, 2015

]]>Aerosols formed from sea spray affect climate change. A new study shows that bromine, which is correlated with ozone depletion, is preferentially found on the surface of these aerosols.

[Phys. Rev. X 5, 011025] Published Tue Mar 03, 2015

]]>The movement of colloidal particles has widespread applications in physics and biology. Particles experiencing an oscillatory electric field exhibit a surprising bifurcation in distance from the electrode.

[Phys. Rev. X 5, 011023] Published Fri Feb 27, 2015

]]>Gauge fields, which appear in the standard model of physics, underpin a variety of fields, including condensed-matter physics. An alternative technique for studying gauge theories using a lattice with quantum degrees of freedom at its vertices is presented.

[Phys. Rev. X 5, 011024] Published Fri Feb 27, 2015

]]>Fundamental biological processes, including the capture of pathogens by membrane receptors, are regulated by molecular transport. Scientists show that receptor functioning is linked to nonergodic dynamics, which refers to the difference between the properties of a particle and an ensemble of particles.

[Phys. Rev. X 5, 011021] Published Wed Feb 25, 2015

]]>Following the time evolution of a large and high-dimensional quantum system is often computationally intractable. A new semiclassical method of modeling quantum dynamics yields surprisingly good results for nonequilibrium dynamics.

[Phys. Rev. X 5, 011022] Published Wed Feb 25, 2015

]]>Fluid-driven deformation of porous materials is relevant to topics ranging from living-tissue growth to natural-gas extraction from shale, but it is difficult to measure in the laboratory. By injecting fluid into a packing of soft particles, researchers shed light on the dynamic interplay between elastic and plastic effects.

[Phys. Rev. X 5, 011020] Published Tue Feb 24, 2015

]]>Researchers show that in bad metals with almost localized electrons, such as heavy-fermion PuCoGa${}_{5}$ and CeCoIn${}_{5}$, $d$-wave superconductivity can be induced by frustrated antiferromagnetic fluctuations near a quantum critical point.

[Phys. Rev. X 5, 011019] Published Mon Feb 23, 2015

]]>Ion beams with high purities have uses in fundamental research and medicine. The CERN ISOLDE’s Laser Ion Source and Trap is used to isolate beams of polonium that have significantly less contamination than previous studies.

[Phys. Rev. X 5, 011018] Published Fri Feb 20, 2015

]]>New results point to surprising differences between fluids of light created in two-dimensional semiconductors and quantum fluids of matter particles. Unless a system is strongly anisotropic, the fluid of light cannot establish a single giant wave as conventional particles do in a Bose-Einstein condensate.

[Phys. Rev. X 5, 011017] Published Thu Feb 19, 2015

]]>A new approach is able to quantify the environmental effects on an evolving organism by analyzing just a small number of surviving individuals.

[Phys. Rev. X 5, 011016] Published Tue Feb 17, 2015

]]>Imaging biological macromolecules allows scientists to accurately probe dynamic molecular structures and engineer drugs. Brief and intense coherent x-ray pulses can yield new forms of data, enabling structure determination without prior-known structural information.

[Phys. Rev. X 5, 011015] Published Thu Feb 12, 2015

]]>Extracting macroscopically relevant quantities from cellular data is challenging. Researchers derive a global relationship to describe the state of growing cells and apply it to *E. coli* bacteria under stress.

[Phys. Rev. X 5, 011014] Published Wed Feb 11, 2015

]]>Superconductivity, the absence of electrical resistance, is rare in quasi-one-dimensional materials. Researchers show that bulk superconductivity emerges at 6.1 K and ambient pressure in a quasi-one-dimensional chromium arsenide.

[Phys. Rev. X 5, 011013] Published Mon Feb 09, 2015

]]>Topological insulators are phases of matter qualitatively distinct from conventional insulators. Researchers use a microwave network analog to switch between topologically nontrivial and trivial states.

[Phys. Rev. X 5, 011012] Published Fri Feb 06, 2015

]]>Topological insulators in three dimensions famously support electronic Dirac cones at their boundary. Researchers show how interactions can effectively strip away their charge, yielding new correlated surface states featuring electrically neutral Dirac fermions.

[Phys. Rev. X 5, 011011] Published Thu Feb 05, 2015

]]>Researchers demonstrate a low-power way to reversibly drive magnetic domain walls using electric fields.

[Phys. Rev. X 5, 011010] Published Tue Feb 03, 2015

]]>Quantum information processing relies on controlling electronic and nuclear spins. Scientists experimentally demonstrate that the spins of a certain kind of optical excitation have relatively long coherence lifetimes and, furthermore, can be reliably controlled.

[Phys. Rev. X 5, 011009] Published Fri Jan 30, 2015

]]>[Phys. Rev. X 5, 019901] Published Fri Jan 30, 2015

]]>Digital, text-based data are being created at a high rate in today’s electronic society. A new algorithm accurately and efficiently assigns topic tags to unstructured text.

[Phys. Rev. X 5, 011007] Published Thu Jan 29, 2015

]]>Several $f$-electron materials undergo sudden changes in equilibrium density and lattice structure, with simultaneous $f$-electron localization or delocalization, given changes in pressure or temperature. New calculations allow a closer look than previously possible at the electronic structure of two such materials, plutonium and praseodymium

[Phys. Rev. X 5, 011008] Published Thu Jan 29, 2015

]]>Insulators and semiconductors are used extensively in industry and a data-driven approach is necessary to investigate the properties of these materials. A new theory of electronic properties is consistent with findings from experiments of transition-metal oxides.

[Phys. Rev. X 5, 011006] Published Wed Jan 28, 2015

]]>Populations that translate energy into motion constitute active matter. New research shows that activity induces a nonequilibrium adhesion between colloidal microspheres, quantified by an activity-dependent equation of state.

[Phys. Rev. X 5, 011004] Published Fri Jan 23, 2015

]]>Complex networks such as power grids, the internet, and brains are characterized by their ability to be both observed and controlled. Symmetries in networks were thought to compromise observability and controllability, but new work shows that this is not always the case.

[Phys. Rev. X 5, 011005] Published Fri Jan 23, 2015

]]>An atom’s walk in an optical lattice is used to test a key principle of quantum physics.

[Phys. Rev. X 5, 011003] Published Tue Jan 20, 2015

]]>Two identical insulators can become charged by touching each other in the presence of an electric field and sufficient humidity.

[Phys. Rev. X 5, 011002] Published Tue Jan 13, 2015

]]>Manufacturing potent drugs requires knowledge of protein receptor sites. A novel strategy, combining the use of a quantum memory with quantum control, can boost the spatial resolution of magnetic-field sensors based on spin defects in diamond, thus achieving nanoscale magnetic imaging of biomolecules.

[Phys. Rev. X 5, 011001] Published Wed Jan 07, 2015

]]>Fractional quantum Hall states are topological quantum fluids observed in two-dimensional electron gases in strong magnetic fields. Researchers show that these electron gases can also harbor a quantum phase transition to an electronic nematic state inside the topological state.

[Phys. Rev. X 4, 041050] Published Tue Dec 30, 2014

]]>Researchers investigate bosonic topological insulators, characterized by exotic surface states, using Monte Carlo simulations.

[Phys. Rev. X 4, 041049] Published Mon Dec 22, 2014

]]>The creation of quantum-correlated photon pairs is a necessary step toward realizing quantum simulation and ultimately quantum computing. Using a millimeter-scale silicon-on-insulator chip, scientists successfully separate correlated photon pairs from background pump photons, where the latter are more numerous by a factor exceeding 10 billion.

[Phys. Rev. X 4, 041047] Published Fri Dec 19, 2014

]]>The periodic input of energy into systems—driving—can have profound effects. Scientists studying driven interacting quantum systems find that a lattice model displays three different regimes as a function of driving period.

[Phys. Rev. X 4, 041048] Published Fri Dec 19, 2014

]]>High-temperature superconductivity may arise from competing or cooperating mechanisms. Researchers show that Raman light scattering can be used to characterize competing superconducting channels in the iron-based compound Ba${}_{0.6}$K${}_{0.4}$Fe${}_{2}$As${}_{2}$.

[Phys. Rev. X 4, 041046] Published Thu Dec 18, 2014

]]>New experimental results show that HgTe functions as a superb three-dimensional topological insulator over a range of applied gate voltages and that the screening of the Dirac surface states stabilizes surface conduction.

[Phys. Rev. X 4, 041045] Published Wed Dec 17, 2014

]]>For wave propagation in a lossy optical medium, the total optical power is commonly expected to decay with propagation distance. Using methods of non-normal operator theory, researchers challenge this notion and show that overall lossy optical materials with a small amount of distributed gain can amplify certain input signals by orders of magnitude.

[Phys. Rev. X 4, 041044] Published Mon Dec 15, 2014

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