Scientists at Yokohama National University (YNU), in collaboration with RIKEN and other institutions in Japan and Korea, have developed a novel method to control electron distribution in molecules using ultrafast terahertz pulses.

Three RIKEN physicists have discovered how tiny tubes of carbon spit out light that is more energetic than the light shone on them. This finding could help to exploit the process in applications such as solar power and biological imaging.

Quantum light sources are fickle. They can flicker like stars in the night sky and can fade out like a dying flashlight. However, newly published research from the University of Oklahoma proves that adding a covering to one of these light sources, called a colloidal quantum dot, can cause them to shine without faltering, opening the door to new, affordable quantum possibilities.

Researchers at North Carolina State University have demonstrated a new technique that uses light to tune the optical properties of quantum dots – making the process faster, more energy-efficient and environmentally sustainable – without compromising material quality.

Excitons, encountered in technologies like solar cells and TVs, are quasiparticles formed by an electron and a positively charged “hole,” moving together in a semiconductor. Created when an electron is excited to a higher energy state, excitons transfer energy without carrying a net charge. While their behavior in traditional semiconductors is well understood, excitons act differently in organic semiconductors. Research by condensed matter physicist Ivan Biaggio focuses on understanding the mechanisms behind exciton dynamics, quantum entanglement, and dissociation in organic molecular crystals.

For the first time, researchers have been able to measure the quantum state of electrons ejected from atoms that have absorbed high-energy light pulses. This is thanks to a new measurement technique developed by researchers at Lund University in Sweden. The results can provide a better understanding of the interaction between light and matter.

Researchers from Case Western Reserve University and the University of Illinois Urbana-Champaign have now discovered another interesting property in diamonds with added boron, known as boron-doped diamonds. Their findings could pave the way for new types of biomedical and quantum optical devices—faster, more efficient, and capable of processing information in ways that classical technologies cannot. Their results are published recently in Nature Communications.

For the first time, scientists have observed a collection of particles, also known as a quasiparticle, that's massless when moving one direction but has mass in the other direction. The quasiparticle, called a semi-Dirac fermion, was first theorized 16 years ago, but was only recently spotted inside a crystal of semi-metal material called ZrSiS. The observation of the quasiparticle opens the door to future advances in a range of emerging technologies from batteries to sensors, according to the researchers. The team, led by scientists at Penn State and Columbia University, recently published their discovery in the journal Physical Review X.

In organic molecules an exciton is a particle bound pair of an electron (negative charge) and its hole (positive charge). They are held together by Coulombic attraction and can move within molecular assemblies. Singlet fission (SF) is a process where an exciton is amplified, and two triplet excitons are generated from a singlet exciton. This is caused by the absorption of a single particle of light, or photon, in molecules called chromophores (molecules that absorb specific wavelengths of light). Controlling the molecular orientation and arrangement of chromophores is crucial for achieving high SF efficiency in materials with strong potential for optical device applications.

A new technique for growing these microscopic crystals, published this week in Science, has not only found a new, more efficient way to build a useful type of quantum dot, but also opened up a whole group of novel chemical materials for future researchers’ exploration.