Science Alert January 27, 2022 Lake Kivu one of Africa’s great Rift lakes lies between Rwanda and the Democratic Republic of Congo. Thousands of years of volcanic activity has caused a massive accumulation of methane and carbon dioxide to dissolve in the depths of Kivu. If triggered, a so-called limnic eruption would cause “a huge explosion of gas from deep waters to the surface” resulting in large waves and a poisonous gas cloud that would put the lives of millions at risk. A company called KivuWatty pumps water saturated with carbon dioxide and methane from around 350 meters (1,150 feet) […]
Author Archives: Hema Viswanath
Harnessing noise in optical computing for AI
Techxplore January 21, 2022 The inherent optoelectronic noises make the photonic systems error-prone in practice. To mitigate and harness noises in photonic computing systems a team of researchers in the US (University of Washington University, Duke University, University of Maryland) has designed and demonstrated a photonic generative network as a part of a generative adversarial network (GAN). The network is implemented with a photonic core consisting of an array of programable phase-change memory cells to perform four-element vector-vector dot multiplication. The GAN can generate a handwritten number (“7”) in experiments and full 10 digits in simulation. They developed an optical […]
In science, small groups create big ideas
Phys.org January 21, 2022 An international team of researchers (Taiwan, Japan) explains the researcher dynamics of generating and developing Emerging Research Topics (ETs) in life sciences and medicine over the past half-century by analyzing the pre-, contemporary-, and post-participation of researchers publishing articles containing the emerging keywords that are elements of ETs. Their results suggest that, while manpower needs for publication have increased, less manpower is required to generate ETs. These trends illustrate a mode shift in the scientific practice of researchers that have generated and developed ETs over the last 50 years as well as highlight the significance of […]
Just listen to the chaos: A new approach to extracting information from large ensembles of sensors
Nanowerk January 24, 2022 In distributed sensing approaches where readouts are obtained directly at the ensemble level, generally requires sensor nodes capable of interacting with each other to implement the required readout statistic. An international team of researchers (Japan, Italy) developed an experimental set up based on chaotic synchronization. They found single-transistor oscillators, representing remarkably low-complexity yet highly flexible entities to be suitable for wireless coupling via mutual induction, realizing a simple form of telemetry for luminous flux. Using numerical simulations and numerous laboratory experiments they demonstrated a rich repertoire of possible interactions among multiple sensor nodes and between the same […]
A leap forward for terahertz lasers
Science Daily January 26, 2022 Despite decades of research, no frequency tunable sources span the terahertz gap between 0.3 and 3 THz. By introducing methyl fluoride (CH3F) as a new gain medium for a quantum cascade laser-pumped molecular laser (QPML), a team of researchers in the US (Harvard University, industry, DEVCOM ARL, Duke University) has demonstrated continuous-wave lasing from more than 120 discrete transitions, spanning the range from 0.25 to 1.3 THz. Due to its large permanent dipole moment and large rotational constants, methyl fluoride (CH3F) as a QPML gain medium combines a lower threshold, a larger power efficiency, and […]
A new record for laser stability across atmospheric distances
Phys.org January 24, 2022 The propagation of laser through turbulent atmosphere is affected by wind and minor equipment vibrations. Researchers in Australia used a host of features to keep the beam stable, including temperature controls, noise reduction and automatic adjustments to the devices holding the equipment. The test involved sending a beam from a building to a site 1.2 kilometers away. The target consisted of a mirror to bounce the laser beam back to a device near the source of the laser. The beam was held in place for approximately five minutes. Once a long-distance means of sending laser signals […]
Recent Review Articles [from the Royal Society of Chemistry]
The Royal Society of Chemistry January 24, 2022 In addition to first reports of new concepts, Materials Horizons publishs topical review and minireview articles. Reviews will be added to this webpage as soon as possible after publication…read more.
Researchers find new way of gaining quantum control from loss
Phys.org January 24, 2022 Researchers in China implemented dissipative spin–orbit-coupled bands filled with ultracold fermions and observed parity-time symmetry breaking as a result of the competition between the spin–orbit coupling and dissipation. Tunable dissipation, introduced by state-selective atom loss, enabled them to tune the energy gap and close it at the critical dissipation value, the so-called exceptional point. Near the critical point, the state evolution exhibited a chiral response, which enabled them to tune the spin–orbit coupling and dissipation dynamically, revealing topologically robust chiral spin transfer when the quantum state encircled the exceptional point. According to the researchers this demonstrates […]
Scientists simulate ‘fingerprint’ of noise on quantum computer
Phys.org January 26, 2022 Traditionally, noise on the quantum device is characterized directly through qubit and gate measurements, but this approach has drawbacks as it does not adequately capture the effect of noise on realistic multi-qubit applications. A team of researchers in the US (University of Chicago, Purdue University) simulated the relaxation of stationary quantum states on a quantum computer to obtain a unique spectroscopic fingerprint of the computer’s noise. In contrast to traditional approaches, they obtained the frequency profile of the noise as it is experienced by the simulated stationary quantum states. Data from multiple superconducting-qubit IBM processors shows […]
Sunlight could be used to power lasers
Phys.org January 25, 2022 Turning the incoherent energy supply provided by the Sun into a coherent laser beam would overcome several of the practical limitations inherent in using sunlight as a source of clean energy. An international team of researchers (France, USA – University of Notre Dame, Italy, Mexico) proposed and designed a bio-inspired blueprint for a novel type of laser with the aim of upgrading unconcentrated natural sunlight into a coherent laser beam. They proposed a laser medium comprised of molecular aggregates inspired by the architecture of natural photosynthetic complexes which exhibit a very large internal efficiency in harvesting […]