applied physics (7)

Scrofulous Signaling...


FIG. 1. Schematics of pulse sequences for spin-locking measurement with (a) two π/2 pulses and (b) two composite pulses. (c) Schematics of a SCROFULOUS composite pulse composed of three pulses. (d) Evolution of the spin state in the Bloch sphere. The spin state is initialized to the |0⟩ state by the first laser pulse. (e) The first π/2 pulse rotates the spin by 90∘ to the (−y)-direction. A y-driving microwave field is applied parallel to the spin in the rotation frame. (f) The second π/2 pulse rotates the spin by 90∘ to the (−z)-direction in the pulse sequence pattern A, or (g) the second −π/2 pulse rotates the spin by −90∘ to the z-direction in the pulse sequence pattern B. Finally, the spin state is read out from the PL by applying the second laser pulse. (h) Schematics of the experimental setup.

Topics: Applied Physics, Electrical Engineering, Materials Science, Optics

We present results of near-field radio-frequency (RF) imaging at micrometer resolution using an ensemble of nitrogen-vacancy (NV) centers in diamond. The spatial resolution of RF imaging is set by the resolution of an optical microscope, which is markedly higher than the existing RF imaging methods. High sensitivity RF field detection is demonstrated through spin locking. SCROFULOUS composite pulse sequence is used for manipulation of the spins in the NV centers for reduced sensitivity to possible microwave pulse amplitude error in the field of view. We present procedures for acquiring an RF field image under spatially inhomogeneous microwave field distribution and demonstrate a near-field RF imaging of an RF field emitted from a photolithographically defined metal wire. The obtained RF field image indicates that the RF field intensity has maxima in the vicinity of the edges of the wire, in accord with a calculated result by a finite-difference time-domain method. Our method is expected to be applied in a broad variety of application areas, such as material characterizations, characterization of RF devices, and medical fields.</em>

Near-field radio-frequency imaging by spin-locking with a nitrogen-vacancy spin sensor, Shintaro Nomura1,a), Koki Kaida1, Hideyuki Watanabe2, and Satoshi Kashiwaya3, Journal of Applied Physics

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Nano Laser...


In their experiments, the researchers used ultrathin crystals consisting of a single layer of atoms. These sheets were sandwiched between two layers of mirror-like materials. The whole structure acts as a cage for light and is called a microcavity.

Topics: Applied Physics, Bose-Einstein Condensate, Lasers, Nanotechnology, Optics

Physicists have taken a step towards realizing the smallest-ever solid-state laser by generating an exotic quantum state known as a Bose-Einstein condensate (BEC) in quasiparticles consisting of both matter and light. Although the effect has so far only been observed at ultracold temperatures in atomically thin crystals of molybdenum diselenide (MoSe2), it might also be produced at room temperature in other materials.

When particles are cooled down to temperatures just above absolute zero, they form a BEC – a state of matter in which all the particles occupy the same quantum state and act in unison, like a superfluid. A BEC made up of tens of thousands of particles behaves as if it were just one giant quantum particle.

An international team of researchers led by Carlos Anton-Solanas and Christian Schneider from the University of Oldenburg, GermanySven Höfling of the University of Würzburg, GermanySefaattin Tongay at Arizona State University, US; and Alexey Kavokin of Westlake University in China, has now generated a BEC from quasiparticles known as exciton-polaritons in atomically thin crystals. These quasiparticles form when excited electrons in solids couple strongly with photons.

“Devices that can control these novel light-matter states hold the promise of a technological leap in comparison with current electronic circuits,” explains Anton-Solanas, who is in the quantum materials group at Oldenburg’s Institute of Physics. “Such optoelectronic circuits, which operate using light instead of electric current, could be better and faster at processing information than today’s processors.”

Anton-Solanas, Schneider, and colleagues studied crystals of MoSe2 that were just a single atomic layer thick. MoSe2belongs to a family of materials known as transition-metal dichalcogenides (TMDCs). In their bulk form, these materials act as indirect band-gap semiconductors. Still, when scaled down to a monolayer thickness, they behave as direct band-gap semiconductors, capable of efficiently absorbing and emitting light.

In their experiments, the researchers assembled sheets of MoSe2 less than a nanometer thick and sandwiched them between alternating layers of silicon dioxide and titanium dioxide (SiO2/TiO2), which reflect light like a mirror. The resulting structure is known as a microcavity and acts as a cage for light. “It’s like trapping the light-emitting material in a room filled with mirrors and mirrors only,” Tongay tells Physics World. “The light gets reflected these mirrors and is absorbed by the material back and forth.”

Exotic quantum state could make smallest-ever laser, Isabelle Dumé, Physics World

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Drops in Cells...


Liquidated3672 (2021), Theodore Lee Jones,

Topics: Applied Physics, Biology, Microscopy, Molecules

A major challenge in cell biology remains to unravel is how cells control their biochemical reaction cycles. For instance, how do they regulate gene expression in response to stress? How does their metabolism change when resources are scarce? Control theory has proven useful in understanding how networks of chemical reactions can robustly tackle those and other tasks.1 The essential ingredients in such approaches are chemical feedback loops that create control mechanisms similar to the circuits that regulate, for example, the temperature of a heating system, the humidity of an archive, or the pH of a fermentation tank.

Theories for the control of biochemical reactions have largely focused on homogeneous, well-stirred environments. However, macromolecules inside cells are often highly organized in space by specialized subunits called organelles. Some organelles, such as the cell nucleus, are bound by a membrane. By contrast, another class of organelles—biomolecular condensates—show the hallmark physical properties of liquid-like droplets, and they provide chemically distinct environments for biochemical reactions.2–4

Such droplets can act as microreactors for biochemical reactions in a living cell (see figure 1). Their liquid nature sustains the fast diffusion of reactants while their specific composition gives rise to the partitioning of reactants in or out of the droplets. In general, the concentrations of reactants inside condensates differ from the concentrations outside. Those differences modify reaction fluxes, which, in turn, can dramatically affect reaction yield and other properties of chemical reactions. Just how such modified fluxes govern the biochemistry inside cells remains poorly understood.

Drops in Cells, Christoph Weber, Christoph Zechner, Physics Today

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Adversary, Friendly, or Neutral...


An unidentified flying object as seen in a declassified Department of Defense video, DoD

Topics: Aerodynamics, Applied Physics, Biology, Exoplanets, General Relativity, SETI

May 17, 2019- No, little green men aren't likely after the conquest of humanity. Boyd's piece for highlights the reason why the Pentagon wants to identify UFOs: they're unidentified. If a warfighter on the ground or in the sky can't ID an object, that creates an issue since they don't know if it's friendly, adversarial, or neutral.

U.S. Navy pilots and sailors won't be considered crazy for reporting unidentified flying objects, under new rules meant to encourage them to keep track of what they see writes Iain Boyd for

Why is the Pentagon interested in UFOs? Intelligent Aerospace

The Pentagon refers to them as "transmedium vehicles," meaning vehicles moving through air, water, and space. Carolina Coastline breathlessly uses the term "defying the laws of physics." So I looked at what the paper might have meant. The objects apparently exceed the speed of sound without a sonic boom (signature of breaking the barrier). Even though this is reported by Popular Mechanics, they're quoting John Ratcliffe, whose name somehow sounds like a pejorative. Consider the source.


U.S. Navy F/A-18 flying faster than the speed of sound. The white cloud is formed by decreased air pressure and temperature around the tail of the aircraft.

The speed of sound is 343 meters per second (761.21 miles per hour, 1,100 feet per second). Mach 1 is the speed of sound, Mach 2 is 1522.41 mph, Mach 3 is 2283.62 mph. NASA's X-43A scramjet sets the record at Mach 9.6 (7,000 mph), so, it's easy to see where Star Trek: The Next Generation got its Warp Speed analog from. The top speed of the F/A-18 is 1,190 mph. Pilots and astronauts under acceleration experience G Forces, and have suits to keep them from blacking out in a high-speed turn.

A Science Magazine article in 1967 reported the dimensions and speeds for the object were undeterminable. reported an object exceeding 70 knots, or 80.5546 mph underwater (twice the speed of a nuclear submarine, so I can see the US Navy's concern). I found some of the descriptions on the site interesting:

5 UFO traits:

1. Anti-gravity lift (no visible means of propulsion), 2. Sudden and instantaneous acceleration (fast), 3. Hypersonic velocities without signatures (no sonic boom), 4. Low observability, or cloaking (not putting this on Romulans, or Klingons), 5. Trans-medium travel (air, water, space).

When I look at these factors, I don't get "little green men." First caveat: there are a lot of planets between us, and them with resources aplenty. Second caveat: any interest an alien intelligence might have in us is as caretakers of an experiment, or cattle. That's disturbing: ever see a rancher have conversations with a chicken, sow, or steer before slaughter?

My hypothesis (Occam's razor) - these are projections, but of a special kind:

For the first time, a team including scientists from the National Institute of Standards and Technology (NIST - 2016) have used neutron beams to create holograms of large solid objects, revealing details about their interiors in ways that ordinary laser light-based visual holograms cannot.

Holograms -- flat images that change depending on the viewer's perspective, giving the sense that they are three-dimensional objects -- owe their striking capability to what's called an interference pattern. All matter, such as neutrons and photons of light, has the ability to act like rippling waves with peaks and valleys. Like a water wave hitting a gap between the two rocks, a wave can split up and then re-combine to create information-rich interference patterns.

Move over, lasers: Scientists can now create holograms from neutrons, too, Science Daily

This of course doesn't explain the decades of observations, since holograms came into being in a 1948 paper by the Hungarian inventor Denis Gabor: “The purpose of this work is a new method for forming optical images in two stages. In the first stage, the object is lit using a coherent monochrome wave, and the diffraction pattern resulting from the interference of the secondary coherent wave coming from the object with the coherent background is recorded on the photographic plate. If the properly processed photographic plate is placed after its original position and only the coherent background is lit, an image of the object will appear behind it, in the original position.” Gabor won the Nobel Prize in 1971 for "his invention and development of the holographic method." Also: History of Holography

This is purely speculative. I have no intelligence other than what I've shared. It does in my mind, explain the physics-defying five traits described above. It does not explain the previous supposition of sightings since humans started recording history, or trying to hypothesize their sightings in antiquity. Solid objects flying at hypersonic speeds make sonic booms; projections - ball lightning, 3D laser, or solid neutron holograms - likely won't.

If these are projections (adversary, friendly, neutral), who is doing them, and why?

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The Power of ASM...



Topics: Alternate Energy, Applied Physics, Atomic-Scale Microscopy, Nanotechnology




When Ondrej Krivanek first considered building a device to boost the resolution of electron microscopes, he asked about funding from the U.S. Department of Energy. “The response was not positive,” he says, laughing. He heard through the grapevine that the administrator who held the purse strings declared that the project would be funded “over his dead body.”     


“People just felt it was too complicated, and that nobody would ever make it work,” says Krivanek. But he tried anyway.  After all, he says, “If everyone expects you to fail, you can only exceed expectations.”


The correctors that Krivanek, Niklas Dellby, and other colleagues subsequently designed for the scanning transmission electron microscope did exceed expectations. They focus the microscope’s electron beam, which scans back and forth across the sample like a spotlight and make it possible to distinguish individual atoms and to conduct chemical analysis within a sample. For his pioneering efforts, Krivanek shared The Kavli Prize in nanoscience with the German scientists Harald Rose, Maximilian Haider, and Knut Urban, who independently developed correctors for conventional transmission electron microscopes, in which a broad stationary beam illuminates the entire sample at once.


Electron microscopes, invented in 1931, long-promised unprecedented clarity, and in theory could resolve objects a hundredth the size of an atom. But in practice, they rarely get close because the electromagnetic lenses they use to focus electrons deflected them in ways that distorted and blurred the resulting images.


The aberration correctors designed by both Krivanek’s team and the German scientists deploy a series of electromagnetic fields, applied in multiple planes and different directions, to redirect and focus wayward electrons. “Modern correctors contain more than 100 optical elements and have software that automatically quantifies and fixes 25 different types of aberrations,” says Krivanek, who co-founded a company called Nion to develop and commercialize the technology.


That level of fine-tuning allows microscopists to fix their sights on some important pursuits, such as producing smaller and more energy-efficient computers, analyzing biological samples without incinerating them, and being able to detect hydrogen, the lightest element, and a potential clean-burning fuel.


The Vast Potential of Atomic-Scale Microscopy, Ondrej Krivanek, Scientific American



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Black Phosphorus...


The black phosphorus composite material connected by carbon-phosphorus covalent bonds has a more stable structure and a higher lithium-ion storage capacity. Credit: DONG Yihan, SHI Qianhui, and LIANG Yan

Topics: Alternative Energy, Applied Physics, Battery, Nanotechnology, Research

A new electrode material could make it possible to construct lithium-ion batteries with a high charging rate and storage capacity. If scaled up, the anode material developed by researchers at the University of Science and Technology of China (USTC) and colleagues in the US might be used to manufacture batteries with an energy density of more than 350 watt-hours per kilogram – enough for a typical electric vehicle (EV) to travel 600 miles on a single charge.

Lithium ions are the workhorse in many common battery applications, including electric vehicles. During operation, these ions move back and forth between the anode and cathode through an electrolyte as part of the battery’s charge-discharge cycle. A battery’s performance thus depends largely on the materials used in the electrodes and electrolyte, which need to be able to store and transfer many lithium ions in a short period – all while remaining electrochemically stable – so they can be recharged hundreds of times. Maximizing the performance of all these materials at the same time is a longstanding goal of battery research, yet in practice, improvements in one usually come at the expense of the others.

“A typical trade-off lies in the storage capacity and rate capability of the electrode material,” co-team leader Hengxing Ji tells Physics World. “For example, anode materials with high lithium storage capacity, such as silicon, are usually reported as having low lithium-ion conductivity, which hinders fast battery [charging]. As a result, the increase in battery capacity usually leads to a long charging time, which represents a critical roadblock for more widespread adoption of EVs.”

Black phosphorus composite makes a better battery, Isabelle Dumé, Physics World

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Gentle breeze: illustration of the B-TENG triboelectric nanogenerator, which harvests electricity that is generated by fluttering polymer strips. (Courtesy: Xin Chen/Xiaojing Mu/Ya Yang)

Topics: Applied Physics, Nanotechnology, Polymers, Research

A new low-cost nanogenerator that can efficiently harvest electrical energy from ambient wind has been created by Ya Yang at the Beijing Institute of Nanoenergy and Nanosystems of the Chinese Academy of Sciences and colleagues. The team reports that the device achieves high electrical conversion efficiencies for breezes of 4–8 m/s (14–28 km/h) and says that it could be used to generate electricity in everyday situations, where conventional wind turbines are not practical.

As the drive to develop renewable sources of energy intensifies, there is growing interest in harvesting ambient energy in everyday environments. From breezes along city streets to the airflows created as we walk, the mechanical energy contained in ambient wind is abundant. The challenge is to harvest this every in an efficient and practical way. This has proven difficult using existing technologies such as piezoelectric films, which operate at very low power outputs.

Yang’s team based their new design around two well-known phenomena in physics. The first is the Bernoulli effect, which causes the fluttering of two adjacent flags to couple. If separated by a very small gap, the flags will flutter in-phase, while at slightly larger separations, they flap out-of-phase, and symmetrically about a central plane. The second is the triboelectric effect – the familiar phenomenon behind the “static electricity” that is created when different objects are rubbed together and then separated – resulting in opposite electrical charges on the objects and a voltage between the two.

Fluttering polymer ribbons harvest electrical energy, Physics World

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