Researchers have developed a chip-based quantum random number generator that provides high-speed, high-quality operation on a miniaturized platform. This advance could help move quantum random number generators closer to being built directly into everyday devices, where they could strengthen security without sacrificing speed.
In a world-first, researchers from the Femtosecond Spectroscopy Unit at the Okinawa Institute of Science and Technology (OIST) have directly observed the evolution of the elusive dark excitons in atomically thin materials, laying the foundation for new breakthroughs in both classical and quantum information technologies.
Their findings have been published in Nature Communications.
Professor Keshav Dani, head of the unit, says, Dark excitons have great potential as information carriers, because they are inherently less likely to interact with light, and hence less prone to degradation of their quantum properties. However, this invisibility also makes them very challenging to study and manipulate.
For almost a century, Heisenberg’s uncertainty principle has stood as one of the defining ideas of quantum physics: a particle’s position and momentum cannot be known at the same time with absolute precision. The more you know about one, the less you know about the other.
In a new study published in Science Advances, our team demonstrates how to work around this restriction, not by breaking physics but by reshaping uncertainty itself.
The result is a breakthrough in the science of measurement that could power a new generation of ultra-precise quantum sensors operating at the scale of atoms.
The Irish mathematician and physicist William Rowan Hamilton, who was born 220 years ago last month, is famous for carving some mathematical graffiti into Dublin’s Broome Bridge in 1843.
But in his lifetime, Hamilton’s reputation rested on work done in the 1820s and early 1830s, when he was still in his twenties. He developed new mathematical tools for studying light rays (or “geometric optics”) and the motion of objects (“mechanics”).
Intriguingly, Hamilton developed his mechanics using an analogy between the path of a light ray and that of a material particle.
The Irish mathematician and physicist William Rowan Hamilton, who was born 220 years ago last month, is famous for carving some mathematical graffiti into Dublin’s Broome Bridge in 1843.
But in his lifetime, Hamilton’s reputation rested on work done in the 1820s and early 1830s, when he was still in his twenties. He developed new mathematical tools for studying light rays (or “geometric optics”) and the motion of objects (“mechanics”).
Intriguingly, Hamilton developed his mechanics using an analogy between the path of a light ray and that of a material particle.
Fluorescent proteins, which can be found in a variety of marine organisms, absorb light at one wavelength and emit it at another, longer wavelength; this is, for instance, what gives some jellyfish the ability to glow. As such, they are used by biologists to tag cells through the genetic encoding and in the fusing of proteins.
The researchers found that the fluorophore in these proteins, which enables the immittance of light, can be used as qubits due to their ability to have a metastable triplet state. This is where a molecule absorbs light and transitions into an excited state with two of its highest-energy electrons in a parallel spin. This lasts for a brief period before decaying. In quantum mechanical terms, the molecule is in a superposition of multiple states at once until directly observed or disrupted by an external interference.
Quantum computers will need large numbers of qubits to tackle challenging problems in physics, chemistry, and beyond. Unlike classical bits, qubits can exist in two states at once—a phenomenon called superposition. This quirk of quantum physics gives quantum computers the potential to perform certain complex calculations better than their classical counterparts, but it also means the qubits are fragile. To compensate, researchers are building quantum computers with extra, redundant qubits to correct any errors. That is why robust quantum computers will require hundreds of thousands of qubits.
Now, in a step toward this vision, Caltech physicists have created the largest qubit array ever assembled: 6,100 neutral-atom qubits trapped in a grid by lasers. Previous arrays of this kind contained only hundreds of qubits.
This milestone comes amid a rapidly growing race to scale up quantum computers. There are several approaches in development, including those based on superconducting circuits, trapped ions, and neutral atoms, as used in the new study.