Now, researchers from the University of Geneva (UNIGE), working with colleagues at the University of Salerno and the CNR-SPIN Institute (Italy), have made a significant breakthrough. They identified a previously unseen geometric feature inside a quantum material that alters how electrons move, in a way similar to how gravity bends light. The findings, published in Science, point to new possibilities for next-generation quantum electronics.

Why Quantum Materials Matter

Modern technologies rely on materials with extraordinary performance, many of which arise from quantum physics. This field focuses on matter at microscopic scales, where particles behave in surprising ways. Over the past century, research into atoms, electrons, and photons led to the invention of transistors and the foundation of today's computers.

Even now, scientists continue to uncover quantum effects that challenge established theories. Recent research suggests that when huge numbers of particles interact inside certain materials, a kind of internal geometry can emerge. This structure can redirect electron motion, closely resembling how Einstein's theory of gravity describes the bending of light.

From Mathematical Idea to Measured Reality

This internal structure is known as the quantum metric. It describes the curvature of the quantum space through which electrons travel and influences many microscopic properties of materials. Despite its importance, proving its existence experimentally has been extremely difficult.

''The concept of quantum metric dates back about 20 years, but for a long time it was regarded purely as a theoretical construct. Only in recent years have scientists begun to explore its tangible effects on the properties of matter,'' explains Andrea Caviglia, full professor and director of the Department of Quantum Matter Physics at the UNIGE Faculty of Science.

Detecting a Hidden Geometry in Quantum Materials

In the new study, the research team led by UNIGE, together with Carmine Ortix, associate professor in the Department of Physics at the University of Salerno, detected the quantum metric at the boundary between two oxide materials, strontium titanate and lanthanum aluminate. This interface is already known as a powerful platform for studying quantum behavior.

''Its presence can be revealed by observing how electron trajectories are distorted under the combined influence of quantum metric and intense magnetic fields applied to solids,'' explains Giacomo Sala, research associate in the Department of Quantum Matter Physics at the UNIGE Faculty of Science and lead author of the study.

Implications for Future Technologies

Being able to observe this effect allows scientists to measure a material's optical, electronic, and transport properties more accurately. The team also found that the quantum metric is a fundamental characteristic of many materials, rather than a rare exception as previously believed.

''These discoveries open up new avenues for exploring and harnessing quantum geometry in a wide range of materials, with major implications for future electronics operating at terahertz frequencies (a trillion hertz), as well as for superconductivity and light-matter interactions,'' concludes Andrea Caviglia.