A new breakthrough from the Zhang Lab at Boston University is making waves in the world of sound control.
Led by Professor Xin Zhang (ME, ECE, BME, MSE), the team has published a new paper in Scientific Reports titled “Phase gradient ultra open metamaterials for broadband acoustic silencing.”
The article marks a major advance in their long-running Acoustic Metamaterial Silencer project.
Quantum distance refers to a measure of quantum mechanical similarity between two quantum states. A quantum distance of one means that the two quantum states are the same, whereas a quantum distance of zero implies that they are exactly the opposite. Physicists introduced this concept in the realm of theoretical science a long time ago, but its importance has been increasingly recognized in the field of physics only in recent times.
In the last few years, many experimental physicists have tried to measure the quantum distance of electrons in real solid-state materials, but a direct measurement of the quantum distance and thus quantum metric tensor—a key geometric quantity in modern physics defined in terms of the distance between nearby quantum states—has remained elusive so far.
Since the quantum metric tensor is highly relevant in explaining and understanding fundamental physical phenomena in solids, it is, therefore, crucial to come up with an effective methodology for its direct measurement in solid-state systems.
Researchers have uncovered the magnetic properties and underlying mechanisms of a novel magnet using advanced optical techniques. Their study focused on an organic crystal believed to be a promising candidate for an “altermagnet”—a recently proposed third class of magnetic materials. Unlike conventional ferromagnets and antiferromagnets, altermagnets exhibit unique magnetic behavior.
“Unlike typical magnets that attract each other, altermagnets do not exhibit net magnetization, yet they can still influence the polarization of reflected light,” points out Satoshi Iguchi, associate professor at Tohoku University’s Institute for Materials Research. “This makes them difficult to study using conventional optical techniques.”
To overcome this, Iguchi and his colleagues applied a newly derived general formula for light reflection to the organic crystal, successfully clarifying its magnetic properties and origin. The work is published in the journal Physical Review Research.
A Copenhagen team has unlocked a clever “backdoor” into studying rare quantum states once thought beyond reach.
Scientists at the Niels Bohr Institute, University of Copenhagen, have discovered a new approach for investigating rare quantum states that occur within superconducting vortices. These states were first proposed in the 1960s, but confirming their existence has proven extremely challenging because they occur at energy levels too small for most experiments to detect directly.
This breakthrough was achieved through a mix of creative problem-solving and the advanced development of custom-made materials in the Niels Bohr Institute’s laboratories. The research findings have been published in Physical Review Letters.
When materials are created on a nanometer scale — just a handful of atoms thick — even the thermal energy present at room temperature can cause structural ripples. How these ripples affect the mechanical properties of these thin materials can limit their use in electronics and other key systems.
New research validates theoretical models about how elasticity is scale-dependent — in other words, the elastic properties of a material are not constant, but vary with the size of the piece of material.
Assistant Professor Jian Zhou, PhD ’18, collaborated with researchers from Argonne National Laboratory, Harvard University, Princeton University and Penn State University for a recently published paper in the Proceedings of the National Academy of Sciences.
Using a semiconductor manufacturing process, the team created alumina structures 28 nanometers thick (more than 1,000 times thinner than the diameter of a human hair) on the silicon wafer with thermal-like static ripples, then tested them with lasers to measure their behavior. To remove possible stress to the material that could affect the results, cantilevers held the wafers during testing.
Understanding how thin materials behave is key to electronics and other technology.
Researchers from the National University of Singapore (NUS) have developed a groundbreaking carbon membrane that could revolutionise proton therapy for cancer patients, and advance technologies in medicine and other areas such as energy devices and flexible electronics.
The new carbon material which is just a single atom thick shows incredible promise in enabling high-precision proton beams. Such beams are key to safer and more accurate proton therapy for cancer treatment. The new material, called the ultra-clean monolayer amorphous carbon (UC-MAC), could outperform best in class materials like graphene or commercial carbon films.
The research was led by Associate Professor Lu Jiong and his team from the NUS Department of Chemistry, in collaboration with international partners.