Jump to Content
View Cart
Facebook
Twitter
rss
E-mail alert
Physics Update
Providing concise yet thorough accounts of research papers from journals devoted to physics and the physical sciences. The department’s items are written and selected by Physics Today staff. After publication online, some of the department’s items appear later in the print issue.
Threading DNA through a nanopore
If a nanopore is sufficiently wide, folded DNA molecules can squeeze through. But where do the folds form?
Hidden order emerges in stream networks
A groundwater flow model reveals that merging tributaries have an affinity for the angle 2π/5.
Making an electrical insulator conduct within a femtosecond
Driven with an ultraintense and ultrashort light pulse, silica’s electrical conductivity can rise and fall by 18 orders of magnitude during a single optical cycle.
Building a better OLED
Organic LEDs are an emerging technology for electronic displays and lighting. And the materials that can be used to make them just got more diverse.
The Hoyle state of carbon-12 unmasked
The building block of life as we know it, carbon forms in stars in a subtle and nontrivial way. Now the veil has been lifted on the structure of a fleeting resonance of that important nucleus.
Damaged, porous materials: A salty tale
A phase transition between hydrated salts is at the heart of a process that corrodes sculptures and buildings.
Taking the shine off copper
Intense laser bombardment creates an array of microcavities that help trap UV, visible, and IR light.
The many facets of "cubic ice"
New evidence shows that a well-known phase of ice is even more complex than thought.
A liquid ground state for 2D helium-3?
New experiments hint at what could be the lowest-density liquid ever found in nature.
An ultrathin film as near-perfect IR absorber
A film of vanadium dioxide is just 1/65 the thickness of the wavelength it absorbs.
Fractionally charged particles not yet seen
In a particle detector at a high-energy collider, anemic ionization would be their calling card.
Cooling molecules the optoelectric way
In a new experiment, the complex rotational and vibrational motions of molecules are not a hindrance but a help.
With medical tape, no pain means great gain
A new design that peels off easily without damaging sensitive skin could be particularly valuable in neonatal care units.
When the universe was slowing down
Results from the Baryon Oscillation Spectroscopic Survey are consistent with standard cosmology and strengthen the case for dark energy.
Tracking Ebola virus within host cells
Confocal microscopy reveals that Ebola virus exploits its host cells' own internal scaffolding to help it self-assemble and move.
Ferroelectric refrigeration
New simulations provide insights into how a cooling effect known since the 1930s might be exploited.
Primed plasmas deliver better ion beams
New theory explains why trains of short laser pulses produce exceptionally uniform plasma shockwaves.
Watching droplets deform in a solid
The first observations of highly electrified droplets in a rubbery polymer reveal the connection between fluid instabilities and the polymer’s dielectric breakdown.
Where did the supersolidity go?
New precautions in the repetition of an old experiment have wiped out its evidence for an exotic quantum phase of matter.
Temperature-sensitive colloids show off a new type of melting
Micron-sized spheres offer a useful model for studying phase-transition dynamics.
Ultracold chemistry in supersonic beams
As the relative motions of reactants become small enough, quantum effects manifest themselves.
Highly charged ions challenge QED
Energy transitions in the three-body systems are intriguingly different from what theory calculates.
Snowfall thickens the East Antarctic ice sheet
In the past three years, ice losses in West Antarctica have been offset by ice gains in East Antarctica.
An optofluidic random laser
The inherent disorder in microfluidic channels may provide an easy road to controllable on-chip lasers.
Serge Haroche and David Wineland share this year's Nobel Prize in Physics
The two quantum opticians are honored "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems."
Extreme water
When submerged wires are exploded, they can transform the most common liquid on Earth into something far more exotic.
A new microscopy tool in the geologist's kit
Coherent nonlinear Raman scattering can be harnessed to image molecular contrasts inside rocks.
A single-atom qubit in silicon
A newly fabricated device can read and write information using the spin of an electron bound to a single atom.
Violating time-reversal symmetry
Predicted half a century ago, time-reversal asymmetry in particle physics has only now been clearly demonstrated.
Imaging fractional differences in chemical bond order
High-resolution atomic force microscopy can map out subtle variations in a molecule’s electronic structure.
Interacting solitary waves
Complex, nonlinear interactions between ocean waves can be frequently observed at beaches near low tide—and may affect tsunamis.
Different photons in, indistinguishable photons out
A recent experiment demonstrates that nonlinear optics can erase frequency differences in photons emitted by solid-state devices.
Filter-free separation of particles by shape
A new technique has the potential to separate healthy red blood cells from misshapen, diseased ones.
A transparent microactuator from a single piece of glass
Made with a one-two punch of femtosecond laser processing and chemical etching, the optomechanical device is ripe for integration into larger systems.
"Chimeras" come to life in the lab
A peculiar coexistence of synchrony and asynchrony has now been seen in experiments.
Flow geometry flattens viscous fingers
A simple gradient in channel depth can suppress the interfacial instability that always occurs when a less viscous fluid pushes against a more viscous one.
The solar cycle and the Sun's shape
The Sun's brightness and surface magnetic activity rise and fall on an 11-year cycle.
A mysterious player on the atmospheric stage
The unidentified molecule reacts with sulfur dioxide, with implications for climate and human health.
Hearing chemical compounds in real time
Multiwavelength photoacoustics can detect and identify trace gases at parts-per-million concentrations.
Earth's natural quasicrystals were delivered from outer space
New analyses of a mineral dug up in the Koryak Mountains of Russia reveal that it formed under extreme conditions during a meteorite collision.
Less trade, quieter seas
By reducing ship traffic, the Great Recession enabled researchers to quantify an important source of low-frequency undersea noise.
Cloud simulations improving in climate models
High-quality data now enable a thorough testing of cloud simulations, which are getting closer to a passing grade.
Platinum hairs give added touch to artificial skin
The thin, flexible sensor can distinguish between a poke, a rub, and a twist.
Most very bright stars have companions
Interaction with binary partners affects the life and death of the heaviest stars.
Archimedes principle, generalized
When a fluid is complex, a favorite buoyancy law breaks down.
Toward a compact microbeam radiotherapy system
Computer simulations boost confidence in a new medical technology that uses carbon nanotubes to generate x rays.
Optical vortex pulses
A new technique offers a stable train of laser pulses with a controllable amount of twist.
Seeing the sound to locate its source
A single laser could replace an array of microphones as a useful tool for locating sounds in air.
Earth’s changing orbit shows up in tree ring data
It takes a sample of tree rings of unprecedented continuity and consistency to reveal a cosmic influence on Earth's climate.
Microfluidic chip sorts the living from the dead
With an appropriate electric field, viable and nonviable cells can be coaxed to migrate in opposing directions.
When a dusty plasma gets dirty
A defocusing technique reveals that particles can stick together in an otherwise pristine plasma “crystal.”
A Higgs particle has been spotted
Further work will show whether it’s the last piece of the standard model or a sign of new physics.
Catching a submarine volcano in the act
Before an eruption, earthquakes and a rising sea floor sometimes herald the event. Detailed measurements reveal the dynamics of volcanism on a mid-ocean ridge.
A puzzling pair of planets
The Kepler orbiter has unveiled two very different exoplanets in closely adjacent orbits.
An eye on an ancient starburst
After a decade of effort, astronomers have pinpointed the brightest submillimeter radiation source in the Hubble Deep Field.
A new imaging technique for analyzing art
Reflected thermal radiation sheds new light on painted surfaces.
Concentration gradients promote antibiotic resistance
A mathematical model suggests how pathogenic bacteria continue to thwart antibiotic treatment.
Plutonium-239 yields to nuclear magnetic resonance
Physicists now have another tool for studying an important nuclear fuel.
Theory meets experiment in the blink of an eye
An ocular puzzle is resolved in a new numerical simulation of human tears.
Artificial materials manipulate heat flow
The layered composites conduct heat anisotropically, to counterintuitive effect.
Graphene phototransistors get gain
By spraying quantum dots onto a graphene flake in a circuit, researchers have produced a phototransistor a billion times as sensitive as any prior graphene-based device.
Spin correlation in top-quark pairs
The standard theory predicts that the ultramassive twins prefer to be born with the same handedness.
A Rydberg-atom photon source
Single photons are a key ingredient in quantum information systems, but producing them on demand is difficult.
Reevaluating NMR coupling
Nuclear magnetic resonance is a mature and powerful tool. But its theoretical underpinning has a significant omission.
DNA-based sensors know what the nose knows
The sensors can “smell” the difference between similar molecules.
Ancient Maya ruins reveal 1200-year-old astronomical tables
Hieroglyphs on the walls of a small building predate well-studied codices by hundreds of years.
Ultrasound with a twist
A device dubbed a sonic screwdriver helps corroborate a fundamental law of angular momentum.
Majorana fermions in a nanowire?
Electrical conductance measurements reveal what may be a massless, chargeless, and spinless quasiparticle of zero energy.
Carbon dioxide and the end of the last ice age
PHYSICS UPDATE: Increasing CO2 preceded the great glacial retreat 18 000 years ago.
Time to reset isotopic clocks?
Two new studies revise key parameters used in radiometric dating.
IceCube fails to see neutrinos predicted from gamma-ray bursts
It now seems unlikely that the bursts can be the only source of ultra-high-energy cosmic rays.
Entangled two-spin qubits
PHYSICS UPDATE: For quantum computation, qubits need to be isolated from their environment but connected to each other. For one kind of spin qubits, a means to achieve both has now been demonstrated.
Doppler sonar in air for border security
We normally think of ultrasound as emanating from a medical device pressed against the body and of sonar as useful mainly for submarines and bats. But now humans can usefully combine the two in open air.
Modeling the impact on Hawaii of the 2011 tsunami
Once the tsunami of last March reached Hawaii, its wave energy took more than six hours to dissipate amid the islands' reefs, channels, and harbors.
Building a virus the simple way
A new model of capsid self-assembly treats biomolecules as balls and springs, with surprisingly good results.
Custom shapes from swell gels
A new lithographic method patterns UV-sensitive, water-absorbing polymers to produce complex, self-folding shapes.
The elusive third neutrino-mixing angle
If none of their three mixing angles is zero, neutrinos may be responsible for the cosmic shortage of antimatter.
Toward an attosecond view of molecules
Theory and experiment combine to examine an important ultrafast process in polyatomic molecules.
Fast times in ferromagnetic alloys
Different constituents play follow-the-leader during demagnetization, with an unexpected yet telling delay.
An optical probe of quantum gravity?
If spacetime is grainy, it may imprint a telltale signature on radiation interacting with a mechanical oscillator in a resonant cavity.
Ultrashort pulses of optical superradiance
A modified commercial diode laser can generate intense flashes of coherent violet light on demand.
Diagnosing thyroid cancer with ultrasound
A new algorithm identifies the malignancy of thyroid nodules on the basis of the nodules' elasticity.
A peek inside a sonoluminescing bubble
Conventional theory says you should be able to see through the tiny bubbles; new experiments say you can’t.
Heating and cooling with electron spins
Researchers exploit the accumulation of polarized spin between two ferromagnetic metals to magnetically control the flow of heat across the interface.
The Little Ice Age
How could a few volcanic winters chill the Northern Hemisphere for half a millennium?
DNA nanobarrel delivers the goods
The barrel opens only in the presence of certain target cells.
How rumors spread
New research shows that anyone can start a rumor, but some people are better positioned to stifle them.
A day on Venus just got longer
The currently accepted value for the planet’s rotation period is inconsistent with a new topographic map of its surface.
Gravity waves perturb the Martian atmosphere's thermal structure
Icy clouds of carbon dioxide that float in the Martian atmosphere can form thanks to the cooling effect of gravity waves.
A self-assembled nanopattern with near-perfect order
Its features are smaller than can be achieved with conventional photolithography.
Criegee chemistry captured
An elusive but atmospherically important molecule yields to kinetic measurement for the first time.
Microlensing search for planets
The Milky Way seems to have more planets than stars
A blind quantum computer’s laboratory debut
Quantum computing promises greater efficiency than classical computing. Quantum communication promises tamper-proof security. Combine the two and you get blind quantum computing.
Frequency-doubled photons can measure current density
The possibility was anticipated theoretically 16 years ago and could be used in applications as a semiconductor diagnostic.
New insights into droplet collisions
The performance of diesel and rocket engines may be improved by exploiting size differences in droplets.
The Arctic gyre spins up to store fresh water
Anticyclonic winds in the Arctic are whipping up a vast reservoir of fresh water that could dissipate if the winds' rotation reverses.
Surface-healing nanoparticles find their target
Transported by specially designed microcapsules, the particles exit only when they arrive at a crack in a damaged material.
Optical-fiber microcavities reach angstrom-scale precision
Locally heating a glass fiber is a surprisingly simple way to create and tune a microresonator.
Hints of the Higgs heighten anticipation
There’s less and less room for particle theory’s long-sought capstone to hide.
Multiple exciton generation
Solar cells based on semiconductor nanocrystals can produce more than one electron–hole pair per incoming photon.
Crevasses may make ice shelves more stable
Periodic arrangements of crevasses produce a bandgap that can prevent flexing in the shelf interior.
A new suitor in the carbon-14 dating game
A tabletop optical system can measure parts per quadrillion traces of the rare carbon isotope.
Tethered proteins speed up photosynthetic electron transfer
The photosynthetic system of an ocean-dwelling bacterium has been wired to allow electrons to quantum mechanically tunnel, rather than diffuse, between its reacting protein species.
Ocean acidification and coral reefs
As the world's oceans continue to absorb atmospheric CO2, the resulting changes could adversely affect coral reefs.
A device-friendly qubit?
Silicon carbide, a material that’s already widely used for electronics, may also be suitable for quantum computation.
Molding many-faced particles
A recently developed technique for mass-producing nanoparticles shows its versatility.
First glimpse of primordial matter
Absorption spectra reveal intergalactic clouds with no elements that require a stellar furnace.
Building ultralight lattices
Using a new method, researchers have produced the lowest-density material ever made.
Wrinkled roaches and flapping flags
The ever-present oblique waves in a flapping flag are primarily responsible for the lift force that offsets the pull of gravity.
Measuring morphological change
Two new algorithms automate a process that used to rely on expert assessments.
Silicon meets the butterfly wing
Inspired by the nanostructures in the wing of a male Papilio ulysses, researchers have made a silicon wafer that both repels water and strongly absorbs light.
A marriage of microscopy and image compression
Instead of looking at a surface pixel by pixel, a new microscope takes a more global view to achieve improved resolution.
Monitoring surface diffusion, one molecule at a time
The symmetry of a molecule affects its adsorption and movement atop an insulator.
Negative ions of molecular hydrogen
The long-standing puzzle of how a hydrogen molecule can hold on to an extra electron for so long has finally been experimentally resolved.
A handheld optical device for image-guided surgery
Near IR lasers, fluorescently tagged nanoparticles, and tomographic reconstruction form the basis of a prototype device that could help surgeons locate and excise tumors.
Aligning scattered light for pain-free diagnostics
A new spectroscopic design that alters the geometry of a key optical element advances the development of a portable noninvasive glucose monitor.
Faking entanglement
Bell’s inequalities are the quintessential test of a system’s nonlocality. But experiments show that the test can be fooled—if one ignores the fine print.
A double take on the double arc
Sometimes, when the nozzle gets in the way, a plasma cutting torch goes haywire. A new study sheds some light on why.
Making waves with the Moon's shadow
As it sails across Earth during a solar eclipse, the lunar shadow creates a bow wave in the ionosphere like a moving boat does in water.
Toward an easily fabricated artificial leaf
Sunlight, silicon, and readily available catalysts turn water into hydrogen and oxygen.
Shifty surfaces bend the rules of ray optics
Researchers have outlined a recipe for fashioning subwavelength optical components from plasmonic antennas.
Vacuum-induced transparency
A subtle quantum interference effect controls how a cloud of atoms in an optical cavity responds to just a single photon.
Discoverers of the accelerating expansion of the universe share this year's physics Nobel
Saul Perlmutter, Adam Riess, and Brian Schmidt are the recipients of this year's Nobel Prize in Physics for their momentous 1998 discovery.
Squeezed light for gravitational waves
By tinkering with light’s quantum fluctuations, researchers have improved the sensitivity of one of the interferometers that they hope will one day detect the elusive gravitational waves.
Shedding light on chiral substrates
Photoemission techniques can be used to tease out the chiral orientation of metal-oxide substrates that selectively adsorb chiral molecules.
Meniscus lithography and Moiré patterns
Evaporation of a trapped liquid can arrange nanoparticles into tunable patterns with long-range order.
World's tiniest combustion chambers
New findings suggest that contrary to conventional wisdom, nanobubbles can host explosions.
Tiny, tangled wires keep photons from reflecting
A simple process for fabricating an antireflective coating may in time be applied to make more efficient solar cells.
Water's response to ultralow magnetic fields comes as a surprise
A record-sensitive nuclear magnetic resonance experiment proves we still don’t know all there is to know about the most abundant liquid on the planet.
Asteroid dust has same composition as meteorites
A sample of asteroid dust has clinched the link between them.
A microfluidics path to harvesting mechanical energy
Embedded in a pair of shoes, circuits composed of a train of conductive droplets can generate a few watts of power—enough to charge a cell phone during a casual stroll.
What's inside a crumpled ball?
Crumpled sheets of paper are a familiar form to most of us, but they still hold many secrets.
Nanoscale electrochemistry
Few energy sources match the energy densities of hydrocarbon fuels. Fuel cells and lithium-air batteries tap into atmospheric oxygen to increase their efficiencies but the nanoscale dynamics are not well understood until now.
Antiproton belt girdles Earth
The orbiting PAMELA charged-particle spectrometer has revealed a significant population of antiprotons magnetically trapped in Earth’s inner Van Allen Belt.
Metal-like microbial nanowires
Protein filaments made by some bacteria may bridge the gap between solid-state electronics and biological systems.
Scalable entanglement in an optical frequency comb
Using a single nonlinear optical element, researchers have entangled dozens of the comb’s optical modes.
Network analysis diagnoses kidney disease
Correlations in the concentrations of hundreds of different biomolecules could provide a way to diagnose obstructive nephropathy early and effectively.
Minimalist model captures water-cycle complexities
Equations inspired by population-dynamics theory may help explain drizzles, downpours, and disappearing clouds.
Acoustic levitation
Though a loudspeaker’s pressure field isn’t nearly strong enough to blow you backward, acoustic pressure can suspend millimeter-sized objects against the force of gravity.
Frequency metrology in ultracold helium
Researchers combine optical trapping and frequency comb technology to control and measure the interaction of light with degenerate quantum gases.
A sound strategy for pollination
A specialized leaf on the vine Marcgravia evenia uses acoustics to lure pollinating bats.
Spin waves and superconductors
Short-range spin waves known as paramagnons are strong enough to hold electron pairs together in high-temperature superconducting cuprates.
A classical oscillator takes the sideband route to the quantum ground state
The cooling and damping of a micromechanical oscillator’s motion to the ground state could pave the way to storage of quantum information and generation of entangled states in mechanical systems.
The chaotic orbits of asteroids and Earth
To properly extrapolate the past and future positions of Earth, one has to include not just the Sun, Moon, and other planets, but also asteroids. Still, such calculations can only go so far.
Antineutrinos reveal a primordial source of Earth’s radiated heat
Every second, Earth expels 44 terajoules of energy into space. Much of that energy arises from the decay of radioactive isotopes but the remainder flows from an energy reservoir created billions of years ago, as our planet formed.
Gravitational lensing of the CMB
With new high-resolution data, researchers can determine that the background has been gravitationally distorted without knowing where the distorting foreground structures are.
An ancient buried landscape
Modeling the erosion history of a now-buried landscape reveals how the rock, which formed under water, was once lifted above sea level.
Protein thermodynamics, measured on the move
Perturbing biomolecules and then watching them relax may be a kind, gentle way to study protein folding in vivo.
Soda cans focus sound to subwavelength spots
A low-tech experiment demonstrates how time-reversal methods and an array of the cans can be used to beat the diffraction limit.
The electron’s electric dipole moment
It hasn’t been found yet, but the limits are getting interesting.
A nanoscale mosaic model of static electricity
A closer look at contact-induced static charge
Tantalizing and rare neutrino oscillation
The first appearance of electron neutrinos amidst an underground beam of muon neutrinos has been reported by Japan's T2K collaboration.
Houston's structures thwart cleansing breezes
A new computer simulation sheds light on why the coastal city sometimes endures dangerous ozone pollution
Stirring superfluids
If you chill helium-3 atoms enough, they settle into a single collective ground state, a Bose–Einstein condensate, that is a superfluid. Theorists can now characterize the vigorous turbulence that results from shaking or stirring in fermionic superfluids.
Fluorescing diamonds inside living cells
Researchers led by the University of Melbourne’s Lloyd Hollenberg have carried out magnetic resonance experiments on individual nanodiamonds placed inside human cells.
Domain walls on the fast track
Researchers in France have figured out how to beat the Walker breakdown, a turbulence-triggering instability that slows down the switching of magnetic moments.
High-spin early stars
First-generation stars were not only very massive, as is generally thought, but also very rapidly spinning, with surface speeds as high as 800 km/s.
Bose-Einstein condensation in the textbook and in the lab
Albert Einstein’s description of Bose–Einstein condensation is based on a statistical argument, but experiences in the lab sometimes diverge from the textbook example.
Optical pump-probe diagnosis for melanoma?
Several noninvasive imaging techniques have been explored to detect skin cancer, but they can't distinguish between melanins. A nonlinear optical pump–probe technique may fix this problem.
Gravity Probe B concludes its 50-year quest
Results of an experiment conceived around 1960 to test general relativity and launched in 2004 were announced at a NASA press conference earlier this month: Albert Einstein’s theory passed.
This Publication
Scitation
SPIN
Scitopia
Google Scholar
PubMed