Terahertz Chip Identifies Short Strands of DNA | MIT Technology Review

Terahertz Chip Identifies Short Strands of DNA | MIT Technology Review: They say that the sequence of bases in an oligonucleotide determines the way in which the strand resonates at frequencies in the terahertz range...

...they have tested it using a device they call a silicon nanosandwich, a quantum well of p-type silicon surrounded by barriers doped with boron. This produces terahertz radiation inside the well where the oligonucleotide is deposited at a concentration that allows a single molecule to enter.

Sound sieve lets you choose what to levitate - tech - 20 June 2014 - New Scientist

Sound sieve lets you choose what to levitate - tech - 20 June 2014 - New Scientist: The team etched a thin brass plate with rectangular strips and suspended it in a tank of water. Ultrasound blasted from above sends acoustic waves through the water that cause the plate to resonate with the bottom of the tank. The resulting sound pressure lifts objects placed below the plate according to size and density.

The team sorted small glass beads from larger ones and pulled glass beads away from tin beads of the same size...

Synchronized brain waves enable rapid learning | MIT News Office

Synchronized brain waves enable rapid learning | MIT News Office:  Brain waves known as “beta bands,” produced independently by the prefrontal cortex and the striatum, began to synchronize with each other. This suggests that a communication circuit is forming between the two regions, Miller says.

“There is some unknown mechanism that allows these resonance patterns to form, and these circuits start humming together,” he says. “That humming may then foster subsequent long-term plasticity changes in the brain, so real anatomical circuits can form. But the first thing that happens is they start humming together..."

Previous studies have shown that during cognitively demanding tasks, there is increased synchrony between the frontal cortex and visual cortex, but Miller’s lab is the first to show specific patterns of synchrony linked to specific thoughts.

Proteins 'ring like bells'

Proteins 'ring like bells': Using modern laser spectroscopy, the scientists have been able to measure the vibrational spectrum of the enzyme lysozyme, a protein that fights off bacteria. They discovered that this enzyme rings like a bell with a frequency of a few terahertz or a million-million hertz. Most remarkably, the ringing involves the entire protein, meaning the ringing motion could be responsible for the transfer of energy across proteins.

The experiments show that the ringing motion lasts for only a picosecond or one millionth of a millionth of a second. Biochemical reactions take place on a picosecond timescale and the scientists believe that evolution has optimised enzymes to ring for just the right amount of time. Any shorter, and biochemical reactions would become inefficient as energy is drained from the system too quickly. Any longer and the enzyme would simple oscillate forever: react, unreact, react, unreact, etc...

Fabrication technique brings metamaterial applications a step closer

Fabrication technique brings metamaterial applications a step closer: The second approach is to pattern a sacrificial substrate and then deposit repeated layers onto it. This 'pattern-first' process suffers from its own difficulties, the most important of which is that the total thickness of the final fishnet material is typically limited to tens of nanometers or less...

Zhou and colleagues were able to increase the total thickness of pattern-first fishnet films to around 300 nanometers, allowing five bilayers of film to be deposited and resulting in a strong characteristic resonance and pronounced metamaterial behavior. To achieve this, they adopted a technique called trilayer lift-off, which is commonly used in industry but seldom applied in research laboratories. It involves patterning a sacrificial layer of a photoresist resting on a layer of silicon dioxide under which lies a second photoresist layer...

Micro-macro entangled 'cat states' could one day test quantum gravity

Micro-macro entangled 'cat states' could one day test quantum gravity: The proposed method involves storing one component of an entangled state of light (consisting of just one or a few photons) in a mechanical resonator (consisting of billions of atoms). During this process, the initial microscopic entangled state of photons is amplified with a strong coherent beam, the photons are converted into phonons, and then the entangled states are retrieved.
This approach makes it possible to create optomechanical "cat states," in which the quantum states of the photons and phonons are in superposition.

How the U.S. Built the World’s Most Ridiculously Accurate Atomic Clock | Science | WIRED

How the U.S. Built the World’s Most Ridiculously Accurate Atomic Clock | Science | WIRED: Both NIST-F2 and the standard it replaces, NIST-F1, are known as cesium-based atomic fountain clocks...

The previous generation of atomic clock was already quite good at figuring out the length of a second but had a few small sources of error. NIST-F1 operates at room temperature and so the walls of the chamber in which the cesium atom ball is tossed heat up, emitting a small amount of radiation. This interferes with the atoms, causing them to shift ever so slightly in their energy levels. By cooling NIST-F2 with liquid nitrogen, the new timepiece reaches temperatures of – 316 degrees Fahrenheit, virtually eliminating this excess radiation and reducing the shifting 100-fold.

The symphony of life, revealed - News Center

The symphony of life, revealed - News Center: Using a technique they developed based on terahertz near-field microscopy, scientists... have for the first time observed in detail the vibrations of lysozyme, an antibacterial protein found in many animals.

The team found that the vibrations, which were previously thought to dissipate quickly, actually persist in molecules like the “ringing of a bell...”

To observe the protein vibrations, Markelz’ team relied on an interesting characteristic of proteins: The fact that they vibrate at the same frequency as the light they absorb...

Markelz and her colleagues exposed a sample to light of different frequencies and polarizations, and measured the types of light the protein absorbed.

World's First Quantum Metamaterial Unveiled | MIT Technology Review

World's First Quantum Metamaterial Unveiled | MIT Technology Review: the split-ring resonators introduced losses because of their internal resistance...

a solution to this problem: use superconducting resonators...

The problem in the past is that physicists had arranged the circuits in series so that the combined state must be a superposition of the states of all the circuits. So if a single circuit was out of kilter, the entire experiment failed.

Macha and co got around this by embedding the quantum circuits inside a microwave resonator–a chamber about a wavelength long in which the microwaves become trapped.

To interact with a photon, each quantum circuit need only couple with the resonator itself and its nearest neighbours.

One-of-a-kind spectrometer reads vibrations between atoms to find structures of molecules

One-of-a-kind spectrometer reads vibrations between atoms to find structures of molecules:

By measuring the vibrations between atoms using femtosecond-long laser pulses, the Rice lab of chemist Junrong Zheng is able to discern the positions of atoms within molecules without the restrictions imposed by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) imaging.
The technique can capture the structure of molecules at room temperature or very low or high temperatures and in many kinds of samples...

 "The atoms in every molecule are always vibrating, and each bond between atoms vibrates at a certain frequency, and in a certain direction," he said. "We found that if we can measure the direction of one vibration and then another, then we can know the angle between these two vibrations – and therefore the angle between the bonds."
He said the researchers begin with the chemical formula and already know, through Fourier transform infrared spectroscopy, how many vibrational frequencies are contained in a given molecule. "Then we measure each vibrational mode, one by one. Once we get all the cross-angles, we can translate this to a model," he said.

Quantum communication controlled by resonance in 'artificial atoms'

Quantum communication controlled by resonance in 'artificial atoms': "We capture the electrons in 'boxes'. Each box consist of a quantum dot, which is an artificial atom. The quantum dots are embedded in the semiconductor and each quantum dot can capture one electron. There needs to be three quantum dots next to each other using nanometer-scale electrostatic metal gates. When we open contact between the 'boxes' the electrons can sense each others' presence. The three spins must coordinate their orientations because it cost extra energy to put electrons with the same spin into the same box. To lower their energy, they not only spread out among the three boxes, but they orient their spins to further lower their energy. The three boxes together form a single entity – a qubit or quantum bit," explains Marcus.

An electrical signal is now sent from outside and by rapidly opening the boxes the system begins to swing in dynamic vibrations. The researchers can use this to change the quantum state of the electrons. "By combining three electrons in a triple quantum dot and oscillating an applied electric field at the frequency that separates adjacent energy levels, we can thus control the spins of the electrons without measuring them," explains Charles Marcus.

Most accurate measurement of Boltzmann constant yet

Most accurate measurement of Boltzmann constant yet: In this study, the researchers... used acoustic thermometry to make the measurement by building an acoustic resonator and making amazingly precise measurements of the speed of sound in argon gas.
The researchers first cooled the resonator to the temperature of the triple point of water so they knew the temperature exactly in the current definition and filled it with argon gas...
Then they used the speed of sound measurement to calculate the average speed of the argon molecules and hence the average amount of kinetic energy that they had – from this they were able to calculate the Boltzmann constant with an extremely high accuracy.

Redesigned Window Stops Sound But Not Air, Say Materials Scientists | MIT Technology Review

Redesigned Window Stops Sound But Not Air, Say Materials Scientists | MIT Technology Review: Their resonance chamber is actually very simple—it consists of two parallel plates of transparent acrylic plastic about 150 millimetres square and separated by 40 millimetres, rather like a section of double-glazing about the size of a paperback book.

This chamber is designed to ensure that any sound resonating inside it acts against the way the same sound compresses the chamber. When this happens the bulk modulus of the entire chamber is negative.

...To maximise this efficiency, they drill a 50 millimetre hole through each piece of acrylic. This acts as a diffraction element causing any sound that hits the chamber to diffract strongly into it.

Predicted state of atomic collapse seen for first time - MIT News Office

Predicted state of atomic collapse seen for first time - MIT News Office: What the new Science paper reports is that atoms sitting on a sheet of graphene — a two-dimensional structure composed of carbon atoms linked in a chicken-wire-like mesh of hexagonal bonds — exactly mimic the properties of atomic nuclei, and can be manipulated to recreate and observe complex atomic phenomena. The key is that while electrons move through graphene as relativistic particles — as though they were massless, even though they actually do have mass — their motion is 300 times slower than that of true massless particles. As a result, the expected phenomenon of collapse should take place at one-three-hundredth the normal nuclear charge — putting it well within reach of experimental observations.

To simulate atomic nuclei, the researchers used pairs of calcium atoms on the graphene surface; they were able to manipulate these pairs (called dimers) on the surface using the probe tip of a scanning tunneling microscope. As soon as three dimers were pushed close together, the surrounding field of electrons showed a specific spectrum of resonances that precisely matched the decades-old predictions of atomic collapse. The observed resonances persisted in a four-dimer and five-dimer artificial nucleus.

Physicists make discovery in the quantum realm by manipulating light

Physicists make discovery in the quantum realm by manipulating light: "In our experiment, we caught and released photons in and from a superconducting cavity by incorporating a superconducting switch," said Yin. "By controlling the switch on and off, we were able to open and close a door between the confined cavity and the road where photons can transmit. The on/off speed should be fast enough with a tuning time much shorter than the photon lifetime of the cavity." She explained that not only can the switch be in an on/off state, it also can be opened continuously, like a shutter. In that way, the research team was able to shape the released photons in different wave forms –– a key element for the next step they want to accomplish: controlled photon transfer between two distant cavities.

Chinese Physicists Build "Ghost" Cloaking Device | MIT Technology Review

Chinese Physicists Build "Ghost" Cloaking Device | MIT Technology Review: Instead, their device takes the light scattered from the apple and distorts it to look like something else such as a banana.  The symmetry of the effect–light is scattered on both sides of the apple–mean that this approach produces two “ghost” bananas, one on each side of the apple...
The big advantage of this approach is that it can be achieved now with existing technology...
They then go on to build a working prototype using concentric cylinders of split ring resonators that operates in 2 dimensions...

'Schrödinger's Hat' Uses Invisibility to Measure Quantum World

'Schrödinger's Hat' Uses Invisibility to Measure Quantum World: Mathematicians now suspect quirks in energy-cloaking metamaterials could be exploited to create powerful quantum probes called "Schrödinger's hats." Such probes might record extremely subtle signals that would otherwise be scrambled by any attempt to measure them.
Yet no ideal metamaterials exist. All slightly betray the existence of objects they conceal, and none completely divert a wide range of energetic frequencies. Some metamaterials even resonate like tuning forks at specific frequencies, sounding like an alarm instead of hiding something. Where some scientists see flaws, however, Greenleaf and his colleagues see opportunity. If the amount of energy going through a metamaterial and the amount of energy coming out are almost perfectly balanced, the resonating metamaterial should trap a signal that describes the environment it was just in. Over time the signal would leak out, allowing researchers to record it.

First ever measurement on atom of pure antimatter

First ever measurement on atom of pure antimatter:  In the latest work, the ALPHA team trapped an atom of antihydrogen using magnetic fields. By shining microwave radiation tuned to a specific frequency on this captive, the team were able to flip the anti-atom's magnetic moment, liberating it from the trap and allowing it to be detected. This process enabled the first spectroscopic measurement of antihydrogen.

Superstuff: When quantum goes big

Superstuff: When quantum goes big: Imagine you have two identical particles, and you swap their positions. The physical system looks exactly the same, and responds to an experiment exactly as before. However, quantum theory records the swap by multiplying their quantum state by a "phase factor". Switching the particles again brings in the phase factor a second time, but the particles are in their original position and so everything returns to its original state. "Since switching the particles twice brings you back to where you were, multiplying by this phase twice must do nothing at all," says John Baez at the Centre for Quantum Technologies in Singapore. This means that squaring the phase must give 1, which in turn means that the phase itself can be equal to 1 or -1.

A Super-Absorbent Solar Material

A Super-Absorbent Solar Material: Atwater worked with Koray Aydin, now an assistant professor of electrical engineering and computer science at Northwestern University, to develop the super-absorber design, which takes advantage of a phenomenon called optical resonance. Just as a radio antenna will resonate with and absorb certain radio waves, nanostructured optical antennas can resonate with and absorb visible and infrared light. The length of a structure determines what wavelength of light it will resonate with. So Atwater and Aydin designed structures that effectively have many different lengths: wedge shapes with pointy tips and wide bases. The thin, nanoscale wedges strongly absorb blue light at the tip and red light at the base.

Atwater and Aydin demonstrated this broadband effect in a 260-nanometer-thick film made of a layer of silver topped with a thin layer of silicon dioxide and finished with another thin layer of silver carved with arrays of wedges that are 40 nanometers at their tips.