“Foundry-Enabled Patterning of Diamond Quantum Microchiplets for Scalable Quantum Photonics” was published by researchers at MIT, KAUST, PhotonFoundries and MITRE.

Abstract

Quantum technologies promise secure communication networks and powerful new forms of information processing, but building these systems at scale remains a major challenge. Diamond is an especially attractive material for quantum devices because it can host atomic-scale defects that emit single photons and store quantum information with exceptional stability. However, fabricating the optical structures needed to control light in diamond typically relies on slow, bespoke processes that are difficult to scale. In this work, we introduce a manufacturing approach that brings diamond quantum photonics closer to industrial production. Instead of sequentially defining each device by lithography written directly on diamond, we fabricate high-precision silicon masks using commercial semiconductor foundries and transfer them onto diamond via microtransfer printing.

In some solid materials under specific conditions, mutual Coulomb interactions shape electrons into many-body correlated states, such as Wigner crystals, which are essentially solids made of electrons. So far, the Wigner crystal state remains sensitive to various experimental perturbations. Uncovering their internal structure and arrangement at the atomic scale has proven more challenging.

Researchers at Fudan University have introduced a new approach to study the Wigner crystal state in strongly correlated two-dimensional (2D) systems. They successfully made sub-unit-cell resolution images of the Wigner crystalline state in a carefully engineered material comprised of a single atomic layer of ytterbium chloride (YbCl₃) stacked on graphite.

The research is published in the journal Physical Review Letters.

Researchers at the University of Basel and ETH Zurich have found a way to flip the magnetic polarity of an unusual ferromagnet using a laser beam. If the approach can be refined and scaled, it points toward electronic components that could be reconfigured with light instead of being permanently fixed.

A ferromagnet acts like it has a built-in internal agreement. Inside the material, enormous numbers of electrons behave like tiny bar magnets because of their spins. When those spins line up, their individual magnetic fields add together, producing the familiar strength that makes a compass needle settle in a direction or lets a refrigerator magnet cling to a door.

That orderly alignment is not automatic, because heat constantly shakes the system. Ferromagnetism appears only when the interactions that encourage alignment win out over thermal motion, which happens below a critical temperature (often called the Curie temperature).

Physicists have observed a strange new quantum phase in a graphene-based system, where a superfluid appears to freeze into a solid-like state. Cooling usually pushes matter through a simple sequence. A gas condenses into a liquid, and with further cooling the liquid locks into a solid. Helium hel