In metals such as copper or aluminum, so-called conduction electrons are able to move around freely, in the same way as particles in a gas or a liquid. If, however, impurities are implanted into the metal's crystal lattice, the electrons cluster together in a uniform pattern around the point of interference, resembling the ripples that occur when a stone is thrown into a pool of water.
The 1962 Nobel Prize James Watson won for his role in the discovery of the structure of DNA is going on the auction block. The auctioneer says the gold medal could bring $2.5 to $3.5 million on Dec. 4. Christie's says it's the first Nobel medal to be offered at auction by a living recipient. Watson made the 1953 discovery with Francis Crick and Maurice Wilkins.
Physicists at the Univ. of Kansas have fabricated an innovative substance from two different atomic sheets that interlock much like Lego toy bricks. The researchers said the new material, made of a layer of graphene and a layer of tungsten disulfide, could be used in solar cells and flexible electronics.
How does glass transition from a liquid to its familiar solid state? How does this common material transport heat and sound? And what microscopic changes occur when a glass gains rigidity as it cools? A team of researchers at New York Univ.'s Center for Soft Matter Research offers a theoretical explanation for these processes in Proceedings of the National Academy of Sciences.
NIF experiments generate enormous pressures in a short time. When a pressure source of this type is applied to any material, the pressure wave in the material will quickly evolve into a shock front. One of NIF’s most versatile and frequently used diagnostics, the Velocity Interferometer System for Any Reflector (VISAR), is used to measure these shocks, providing vital information for future experiment design and calibration.
Scientists at the world's largest smasher announced today that they have discovered two new subatomic particles never seen before that could widen our understanding of the universe. An experiment using the European Organization for Nuclear Research's Large Hadron Collider found the new particles, which were predicted to exist, and are both baryons made from three quarks bound together by a strong force.
Inspired perhaps by Harry Potter's invisibility cloak, scientists have recently developed several ways to hide objects from view. The latest effort, developed at the Univ. of Rochester, not only overcomes some of the limitations of previous devices, but it uses inexpensive, readily available materials in a novel configuration.
A team of scientists hope to trace the origins of gamma-ray bursts with the aid of giant space microphones. Researchers at Cardiff Univ. are trying to work out the possible sounds scientists might expect to hear when the ultra-sensitive LIGO and Virgo detectors are switched on in 2015.
Univ. of Tennessee, Knoxville’s College of Engineering has made recent headlines for discoveries that, while atomically small, could impact our modern world. The team focused on the role of epilayer-substrate interactions in determining orientational relations in van der Waals epitaxy.
For such humble creatures, single-celled paramecia have remarkable sensory systems. Give them a sharp jab on the nose, they back up and swim away. Jab them in the behind, they speed up their swimming to escape. But according to new research, when paramecia encounter flat surfaces, they’re at the mercy of the laws of physics.
New research by a team of European physicists could explain why the universe did not collapse immediately after the Big Bang. Studies of the Higgs particle have suggested that the production of Higgs particles during the accelerating expansion of the very early universe (inflation) should have led to instability and collapse.
A team of New York Univ. and Univ. of Barcelona physicists has developed a method to control the movements occurring within magnetic materials, which are used to store and carry information. The breakthrough could simultaneously bolster information processing while reducing the energy necessary to do so.
Physicists at Australian National Univ. have engineered a spiral laser beam and used it to create a whirlpool of hybrid light-matter particles called polaritons. The ability to control polariton flows in this way could aid the development of completely novel technology to link conventional electronics with new laser and fiber-based technologies.
For the first time, scientists have vividly mapped the shapes and textures of high-order modes of Brownian motions—in this case, the collective macroscopic movement of molecules in microdisk resonators—researchers at Case Western Reserve Univ. report. To do this, they used a record-setting scanning optical interferometry technique.
A study at the SLAC National Accelerator Laboratory suggests for the first time how scientists might deliberately engineer superconductors that work at higher temperatures. In their report, a team of researchers explains why a thin layer of iron selenide superconducts at much higher temperatures when placed atop another material, which is called STO for its main ingredients strontium, titanium and oxygen.
While the Martinis Lab at the Univ. of California, Santa Barbara has been focusing on quantum computation, they have also been exploring qubits for quantum simulation on a smaller scale. The team worked on a new qubit architecture, which is an essential ingredient for quantum simulation, and allowed them to master the seven parameters necessary for complete control of a two-qubit system.
Researchers at The Univ. of Texas at Austin have achieved a milestone in modern wireless and cellular telecommunications, creating a radically smaller, more efficient radio wave circulator that could be used in cellphones and other wireless devices, as reported in Nature Physics. The new circulator has the potential to double the useful bandwidth in wireless communications by enabling full-duplex functionality.
What time is it? The answer, no matter what your initial reference may be, will always trace back to the atomic clock. The international standard for time is set by atomic clocks—room-sized apparatuses that keep time by measuring the natural vibration of atoms in a vacuum. The frequency of atomic vibrations determines the length of one second.
X-rays are widely used in medicine and in materials science. To take a picture of a broken bone, it’s enough to create a continuous flux of x-ray photons, but in order to study time-dependent phenomena on very short timescales, short x-ray pulses are required. One possibility to create short hard x-ray pulses is hitting a metal target with laser pulses.
A study conducted in part at the SLAC National Accelerator Laboratory has revealed how a key human protein switches from a form that protects cells to a form that kills them—a property that scientists hope to exploit as a “kill switch” for cancer. The protein, called cIAP1, shields cells from programmed cell death, or apoptosis.
For more than 50 years, scientists have debated what turns particular oxide insulators, in which electrons barely move, into metals, in which electrons flow freely. Some scientists sided with Nobel Prize–winning physicist Nevill Mott in thinking direct interactions between electrons were the key. Others believed, as did physicist Rudolf Peierls, that atomic vibrations and distortions trumped all.
A team of engineers and scientists has identified a source of electronic noise that could affect the functioning of instruments operating at very low temperatures, such as devices used in radio telescopes and advanced physics experiments. The findingscould have implications for the future design of transistors and other electronic components.
In classrooms and everyday conversation, explanations of global warming hinge on the greenhouse gas effect. In short, climate depends on the balance between two different kinds of radiation: The Earth absorbs incoming visible light from the sun, called “shortwave radiation,” and emits infrared light, or “longwave radiation,” into space.
Scientists from SLAC National Accelerator Laboratory and the Univ. of California, Los Angeles have shown that a promising technique for accelerating electrons on waves of plasma is efficient enough to power a new generation of shorter, more economical accelerators. This could greatly expand their use in areas such as medicine, national security, industry and high-energy physics research.
The process of phase changes- those transitions between states of matter- is more complex than previously thought. A team researchers has found that we may need to rethink one of science’s building blocks and illustrate how a proper theoretical description of transitions has remained unclear.