Graviton to photon conversion via parametric resonance https://www.sciencedirect.com/science/article/pii/S2212686423000365z
In a groundbreaking discovery, physicists have found that gravity can create light under certain conditions, opening up new avenues of research in astrophysics and cosmology.
New findings using data from NASA’s IXPE (Imaging X-ray Polarimetry Explorer) mission offer unprecedented insight into the shape and nature of a structure important to black holes called a corona. The findings are published in The Astrophysical Journal.
The system that produced this outburst is referred to as CXOU J005245.0–722844. It was recently identified by members of the Einstein Probe team and confirmed by the Swift team as the seventh-known example of a Be/White Dwarf X-ray binary. Be/White Dwarf binaries are binary systems in which a white dwarf star orbits a hot young star surrounded by a disk of stellar material. Astronomers expect these binaries to be commonly observed, Gaudin said, and the lack of known examples is a mystery.
“Novae are explosions that happen when material from a nearby star is deposited onto the surface of a white dwarf,” Gaudin said. “After enough material has been built up, the surface undergoes rapid thermonuclear fusion which creates the outburst. Most novae are events that reach moderate luminosities and decay over the course of several weeks. This nova is strange not just in its extremely luminous behavior but also in its short duration.”
The thermonuclear reaction during the nova is similar to a massive hydrogen bomb exploding—the explosion produces electromagnetic radiation that can be seen by telescopes on Earth and in orbit around Earth. According to the researchers, the nova was visible at optical wavelengths, or visible light, for just under a week and in X-rays for just under two weeks.
From subatomic particles to complex molecules, quantum systems hold the key to understanding how the universe works. But there’s a catch: when you try to model these systems, that complexity quickly spirals out of control—just imagine trying to predict the behavior of a massive crowd of people where everyone is constantly influencing everyone else. Turn those people into quantum particles, and you are now facing a “quantum many-body problem.”
Quantum defects have the potential to act as ultra-sensitive sensors that could offer new kinds of navigation or biological sensor technology.
In their previous research, Mak and his colleagues engineered a highly tunable moiré Kondo lattice system based on MoTe2/WSe2 moiré bilayers. This material offers a unique opportunity to examine the Kondo destruction transition in a continuous manner, which has proved highly challenging in bulk heavy fermion materials.
“With this background, our Nature Physics paper studied the fate of the heavy fermions by continuously tuning the density of the itinerant carriers in the system, which tunes the effective Kondo coupling strength,” said Mak. “Near a critical density, we observed a destruction of the heavy fermions and the simultaneous emergence of a ferromagnetic Anderson insulator.”
As part of their new study, the researchers examined the Kondo lattice physics emerging in the moiré semiconductor: angle-aligned MoTe2/WSe2 heterobilayer presented in their previous paper. Their results highlight the promise of moiré Kondo lattices for studying the Kondo destruction transition using a tunable platform, as well as the possibility of realizing other exotic states of matter near such transition.
When driving though a bank of fog, car headlights are only of limited help as the light is scattered by the water particles suspended in the air. The situation is similar when you try to observe the inside of a drop of milk in water or the internal structure of an opal gem with the help of white light. In all these cases, multiple light scattering effects prevent examination of the interior.
A new study opens the door to cutting-edge solutions that could contribute to the realization of a system capable of processing quantum information in a simple yet powerful way.
Physicists at RIKEN have demonstrated how ultrafast, low-power-consumption memory devices could be realized by replacing conventional magnetic materials with novel ones.
A research team has successfully achieved an atomically controlled insulator-to-metal transition in iridate/manganate heterostructures. Their findings were recently published in Nature Communications.
