Category archives: Quantum physics

Somewhere between the microscopic realm of elementary particles and the macroscopic world of human beings, something strange happens: The rules of quantum physics, which work so exquisitely for tiny atoms, seem to lose their grip as objects grow larger. Pondering where and how this shift from small-scale quantum fuzziness to everyday sharp certainty happens gives […]

Nickel disulfide, NiS₂, is an unusual material. Its interior behaves as an electrical insulator, blocking the flow of current, while certain parts of its surface conduct electricity freely. This contradiction has puzzled physicists for decades, and a recent study offers a detailed explanation. The conduction, it turns out, is confined to tiny one-dimensional steps on […]

Many of today’s electronic devices — from the semiconductors in your cell phone to the photovoltaic cells in your solar panels — are built on thin-film substrates. The thin film is an electronically conductive material while the substrate is an inert material. Or is it? Physicists and materials scientists have long assumed substrates do not […]

Over a century ago, quantum physics revealed a surprising fact: truly identical particles do not behave like tiny billiard balls. When two indistinguishable particles meet under the right conditions, they can interfere with each other in ways that have no classical explanation. One of the most famous demonstrations of this phenomenon is the Hong–Ou–Mandel effect […]

The idea sounds almost like science fiction: two tiny particles that are quantum mechanically linked might also be connected by microscopic shortcuts through spacetime itself, tiny wormholes. This possibility, known as the ER = EPR conjecture, has become a serious topic at the frontier where quantum mechanics meets gravity. The entanglement-is-just-a-wormhole idea The initials point […]

Author: Howard Wiseman, Director, Centre for Quantum Dynamics, Griffith University As Homer tells us, Odysseus made an epic journey, against the odds, from Troy to his home in Ithaca. He visited many lands, but mostly dwelt with the nymph Calypso on her island. We can imagine that his wife, Penelope, would have asked him about […]

Few concepts in physics are as familiar, yet as enigmatic, as time. In Einstein’s theory of relativity, time is not absolute: its passage depends on motion and gravity. But when combined with quantum physics, this relativistic form of time becomes even more counterintuitive. Testing quantum superpositions of time According to quantum theory, the flow of […]

In the world of quantum materials, some of the most important discoveries come not from finding new particles, but from learning to see familiar electrons in a new way. A striking example comes from a single layer of niobium diselenide, a crystal just one layer thick, where researchers have now directly mapped a hidden pattern […]

Every time a computer processes information, electrons shuttle through circuits carrying electric charge, and much of the energy they carry is wasted as heat. Spintronics proposes a different approach: instead of relying solely on the charge of electrons, exploit another of their properties called spin, a quantum-mechanical quantity that can be thought of as a […]

Imagine taking two identical sheets of chicken wire and laying them on top of one another. If you align them perfectly, they look like a single sheet. But if you rotate the top layer by just a tiny amount, a beautiful large-scale crawling pattern emerges. In physics, we call this a Moiré pattern. When we […]