A quantum thermometer that measures temperatures in space-time

Oct. 17 () –

Australian scientists have led the design of a quantum thermometer to measure the ultracold temperatures of space and time. predicted by Einstein and the laws of quantum mechanics.

Physics Professor James Q. Quach, from the University of Adelaide, a member of the Institute for Photonics and Advanced Sensing (IPAS), said it’s a statement: “We have designed a quantum thermometer that can measure extremely small temperature changes. The theoretical design of the quantum thermometer is based on the same technology used to build quantum computers.”

Einstein predicted that the speed at which time is perceived to pass depends on the speed at which you are traveling: a person who is moving very fast ages at a slower rate than someone who is standing still. This led to his Theory of General Relativity, which says that space and time together they act like a fabric that can flex and deform.

The relationship between temperature and acceleration is similar to the relationship between time and speed. Different observers moving at different accelerations would perceive different, albeit minute, temperature differences.

“In 1976, Canadian physicist William Unruh combined Einstein’s work with the other fundamental theory of modern physics, quantum mechanics, and predicted that the fabric of space-time has a very low temperature,” said Dr Quach.

“Curiously, this temperature changes depending on how fast you move. To see this change in temperature, you would have to be moving extremely fast. To see even a one degree change in temperature, you’d have to get close to the speed of light. Until now, these extreme speeds have prevented researchers from verifying Unruh’s theory.

Dr Quach and his colleagues, Professor William Munro of NTT Basic Research Laboratories in Japan and Professor Timothy Ralph of the University of Queensland, published their work in the journal Physical Review Letters.

“In theory, a quantum thermometer doesn’t need to physically accelerate, but instead uses a magnetic field to accelerate the device’s internal energy gap,” says Dr. Quach, which highlights that the quantum thermometer can be built with current technology.

The team’s work has important implications for future research. The quantum thermometer can be used to measure ultracold temperatures and with an accuracy that conventional thermometers cannot.