Composite thin films composed of ferromagnetic metallic manganite La${}_{0.7}$Ca${}_{0.3}$MnO${}_3$ (LCMO) and multiferroic BiFeO${}_3$ (BFO) host a novel magnetotransport phenomenon at the interface that can be controlled by switching the ferroelectric polarization in BFO. A new experiment reveals that suppression by BFO of the polaronic coupling between electrons and Mn ions in LCMO frees the electron and enables the transport.

Could blowing your nose into a “smart tissue” help detect a viral infection? Theorists say “yes” with a proposal for such a smart tissue: a hydrogel film with embedded prestretched DNA molecules.

Surface plasmons, electromagnetic fields generated by the charge oscillations at the surface of a light-illuminated metallic nanoparticle, are typically described in terms of effective electric dipoles and their dynamics. Scientists discover that adding periodic grooves to the surface of subwavelength metallic disks creates localized surface plasmons of magnetic character in addition to the typical electric ones.

Highly sensitive, high-speed control and detection of light–quantum-state interactions in nanoscale quantum devices such as quantum dots is key in quantum technology. Scientists achieve real-time detection of single-charge jumps in a quantum dot by amplifying its interaction with photons using a micropillar optical cavity and measuring the interaction with a high-speed technique.

Removing electrons in a polyatomic molecule from their orbitals can split the molecule into two ionic fragments. The precise fragmentation pathway taken depends on the molecular orbitals. Scientists show that selective fragmentation can be achieved by controlling the intensity and duration of the laser pulses used to remove the electrons.

The spectral purity of quantum cascade lasers (QCL) suggests their use in high-precision metrology applications at terahertz wavelengths. By combining a QCL with a THz frequency comb, scientists have been able to measure the frequency of a rotational transition of a gas (methanol) with a record-breaking precision of four parts in one billion.

State-of-the-art quantum Monte Carlo simulations of the electrodynamic properties of disordered superconductors lead to many new insights about the disorder-driven superconductor-insulator transition.

Recent benchmarking of the computational speedup of quantum “annealing” machines of the D-Wave-2 type shows that they do not perform faster than a standard desktop computer. A timely theoretical study of the computational tests used in the benchmarking explains why that may be the case.

Silicon-based laser sources could bring tremendous advances to science and technology. But, laser generation in pure silicon is fundamentally forbidden. Now scientists demonstrate experimentally the feasibility of laser generation in boron-doped silicon.

Fundamental understanding of nonequilibrium phase transitions in quantum many-body systems is still in its infancy but is urgently needed given the recent surge in exploration of light-matter interactions in a variety of quantum systems. A field-theoretical renormalization group study of a light-driven, dissipative model system of bosons contributes an important piece.

How do closed quantum systems reach equilibrium? By knocking an ultracold atomic gas out of its spin-state equilibrium and imaging its approach to equilibrium, scientists bring this process to light.

An ultracold mixture of two different species of fermionic atoms can turn into a quantum coherent “superfluid” at certain mixing ratios as the fermions overcome their natural repulsion to pair up. Tuning the mixing can destroy the superfluid. A theoretical study shows that the breakdown of the superfluid corresponds to a new type of quantum critical point that is experimentally accessible.

A natural nonequilibrium process that takes a system from one equilibrium state to another in a short time always involves dissipation. But, it’s actually possible in quantum control to design and implement dissipationless “shortcuts” for quantum systems. Scientists add a few concrete practical tools for achieving this goal.

“Going viral” is a familiar phrase in the world of social media, but fundamental scientific understanding of the mechanism(s) of “viral” spreading in interconnected multilayer networks is very limited. A new statistical-physics study reveals when and how fast spreading results from correlation between lateral (intralayer) and vertical (interlayer) spreading.

Optical cavities are used to amplify light-matter interactions that are essential to many quantum technologies, but the ideal characteristics of a high quality factor and a low mode volume are difficult to achieve simultaneously. Now, a theoretical study shows that subwavelength spherical cavities composed of multiple concentric metal-dielectric bilayers can meet this challenge.

Cellular biochemical machines such as the ribosome distinguish the right molecules from the wrong ones with similar chemical structures with an astonishing level of accuracy. How do they do that? Theorists now show that a nonequilibrium biochemical system can indeed use external energy to perform accurate molecular “proofreading.”

Surface impedance of a photonic material governs how an impinging light wave behaves at its surface, whereas its bulk “band structure” determines what wave modes can propagate in it. Is there a surface-to-bulk correspondence? A new study of one-dimensional photonic crystals indeed uncovers a rigorous fundamental relationship between the two.

Isolated Majorana fermions have been known to obey non-Abelian particle statistics. Pairs of bound Majorana fermions are now predicted to exist in topological superconductors with time-reversal symmetry. What type of statistics do such pairs obey? Theorists show for the first time that, “protected” by time-reversal symmetry, they obey a new type of non-Abelian statistics.

Microwave circulators, which perform one-way routing of microwave signals in ultralow-temperature devices, are essential in quantum technology; but currently used circulators are too bulky for future quantum computer applications. A fundamentally different approach based on an innovative use of the Hall effect promises excellent performance at much smaller scales.

Faraday waves—nonlinear standing waves that appear on the surface of a vibrated liquid—can self-organize into a regular lattice of oscillating solitons (oscillons), which then “melts” into a disordered array as the driving amplitude increases. In a new experiment, tracer particles in a vibrated liquid reveal that the oscillon lattice generates two-dimensional turbulence that leads to its own melting.

Undular bores, e.g., large tidal waves that travel upstream in river estuaries, are a fascinating nonlinear wave phenomenon. The conditions needed to create them also occur in optical systems. A new experiment using four-wave mixing to generate multiple undular bores and their interactions in optical fibers provides an opportunity to study them in a laboratory setting.

Cell-cell or cell-substrate adhesion was long thought to be controlled only by protein molecules embedded in the cell membrane, but more recently, the little-understood membrane-membrane or membrane-substrate interaction has been added to the mix. Scientists deploy a combination of state-of-the-art experimental tools and theoretical modeling to gain valuable knowledge of this interaction.

Computational epidemiology uses algorithms to identify and eradicate viruses. Researchers investigate targeted immunization as an optimization problem for a given choice of parameters and costs.

Artificially engineered materials—metamaterials—typically alter only one heat or electromagnetic parameter at once. Researchers test a metamaterial that behaves simultaneously like a thermal concentrator and an electrical invisibility cloak.

Metamaterials, artificial structures with unexpected properties, only function over a limited spectral window. Scientists have recently determined that the technique of combining a metallic metamaterial with a dielectric interlayer creates a device that modulates light over a wide range of frequencies.

Many technologies use magnetic materials based on rare-earth metals. Group $3d$, $4d$, and $5d$ transition metals can be replacements for scarce rare-earth metals—researchers have determined that the magnetocrystalline properties of YCo${}_5$, a prototypical ferromagnet, depend strongly on dynamical electron correlations.

Lasers can be used to steer an electron, yielding extreme-ultraviolet light pulses when the accelerated electron recollides with its parent atom. Researchers have enhanced the flux of the extreme-ultraviolet pulses by a factor of 100, enabling the study of extremely fast (subfemtosecond) electron dynamics.

Solar cells typically rely on diamond silicon, but researchers have found that hydrogenated bilayer silicene absorbs visual light better and can be used to create efficient thin-film solar absorbers and silicon-based, white-light-emitting diodes.

Ultralight bosons are prime dark matter candidates. Scientists propose using nuclear magnetic resonance techniques to search for such particles with masses as low as 10${}^{-12}$ eV.

Social networks experience viral spreading, in which a small group of pioneering individuals can popularize movements and ideas. Scientists use physical modeling and empirical validation to trace how networks shrink and grow depending on the actions of both random nodes and well-connected nodes.

The waves from cardiac tissues and brain activity are examples of rhythmic spatiotemporal patterns. A new theory describes these patterns, free of assumptions about the patterns’ rigidities or translational symmetries, paving the way for controlling these patterns in chemical and biomedical engineering.

Holding single ultracold atoms in reconfigurable arrangements makes it possible to study quantum systems. Researchers demonstrate two-dimensional arrays of optical tweezers containing up to 100 traps that can be configured in arbitrary geometries.

Magnetic domain walls, used in computer bubble memories in the 1970s, are now garnering new research interest. Scientists predict that, in a class of transition-metal-oxide semiconductors, 2D metallic layers are spontaneously formed at magnetic domain walls, shedding light on why these semiconductors are notoriously poor insulators, regardless of their chemical composition.

Researchers develop a new theory to characterize anomalous spatial diffusion of an ensemble of cold ${}^{87}$Rb atoms and single ${}^{24}$Mg${}^{+}$ ions in optical lattices. The theory shows how a transition from regular to anomalous diffusion, with a continuous range of anomalous scaling, is obtained with the tuning of the laser intensity.

Coupling photoluminescent emitters to photonic nanostructures depends critically on the emitter orientation. Researchers show that emission polarization analysis can be used to measure the three-dimensional orientation of single nanoemitters, making it possible to isolate nanoemitters whose orientations are favorable for specific nanostructure cavities.

Data-intensive medical tests require scientists to distill relevant information from massive datasets. Researchers now show that entropy—a concept traditionally used in statistical physics—can characterize both leukemic and normal cell populations, enabling correct diagnoses of leukemia.

Scientists study complex networks of neurons using a formulation that accounts for how neuron connection probability depends on spatial separation. Their results show that the spatial and temporal dynamics of neuronal networks can be predicted at the macroscopic level, even though the microscopic activity is chaotic.

How do quantum-mechanical effects contribute to the properties of graphene? Researchers examine how different quantum-mechanical scenarios are reflected in the cohesive force between micron-sized graphene flakes. Measurements of this force will shed light on the mechanism of self-assembly of graphene-based nanostructures.

D-wave computers are designed to implement a single quantum algorithm called quantum annealing. Are these computers really quantum? Researchers have found strong evidence that qubits in a processor running the algorithm are entangled quantum mechanically.

Theorists show via numerical analyses that strained graphene exhibits a novel form of magnetism in which ferromagnetism is observed only on local scales; the total magnetization is actually zero.

Futuristic technologies of quantum communication and encryption rely on verifying quantum-mechanical principles. Scientists experimentally show that a measurement-disturbance relationship, similar to Heisenberg’s uncertainty principle, is satisfied using a two-level qubit system.

Recent breakthrough demonstrations of the measurement and control of a single atom’s electrons and nuclear spins in silicon have added momentum to the pursuit of quantum computing. New results show that two-qubit quantum logic gates can perform with high fidelity, without the need for placing atoms with subnanometer precision.

Interferometry plays a key role in new technologies such as atomic clocks and optical magnetometers. Scientists experimentally confirm that nonlinear measurements of atomic spin achieve state-of-the-art sensitivities that surpass the best possible linear measurements.

Rabi models—describing how two-level atoms interact with fields—are used in quantum optics, solid-state physics, and mesoscopic physics. Now scientists extend their range of applications further by calculating the energies and eigenstates of an anisotropic Rabi model.

In a game of duplicate bridge, better information sharing between two partners about their cards means better chances of winning. Researchers devise, and experimentally demonstrate, the first quantum information-sharing protocol that lets players improve their bids, expanding the understanding and use of quantum resources.

Superradiance, originally proposed by Dicke in 1954, has been recorded in both quantum and classical systems. Now, researchers use photonics crystals to experimentally verify the presence of superradiant states and the nonlinear dynamics of the Dicke transition.

Quantum computing promises to tackle computational problems that are intractable with classical computers. Researchers demonstrate that spin ensembles can store quantum information over longer times than previously achieved, a significant step toward a quantum memory.

Quantum chromodynamics and quantum magnetism, while appearing at first to be disparate fields, can be linked. Using a random matrix description, theorists show how the two paradigms map to one another.

At half filling of the $d$ electron shell, the interplay of crystal-field interactions, spin-orbit couplings, and on-site Coulomb repulsion gives rise to very rich physics. Unconventional ground states and magnetic properties have recently been found in 5$d^5$ oxide compounds such as Ba${}_2$IrO${}_4$, which requires a revision of standard concepts in superexchange theory.

Sensors in optical cavities can be used for measuring acceleration, fields, and particles. New research reveals a record sensitivity for detecting small amounts of torque within optical cavities, useful for detecting magnetic fields.

New results show that filamentous viruses behave mainly like hard rods, providing a simple way, based on entropy alone, of modeling the thermodynamics and self-organization behavior of more complex condensed matter systems.