Whether we are waiting for a car windshield to defrost in winter or a warm drink to cool down, how long it takes for an object to settle into a stable, even temperature within its environment (thermal equilibrium) depends on numerous factors. These can include surface area, the material properties of an object and airflow.

But when we zoom down to the subatomic scale, such as where qubits operate in a quantum computer, a different set of rules takes over. External conditions still matter, but according to a new paper published in the journal Nature Physics, quantum mechanics sets a fundamental speed limit on how quickly a process can bring different quantum systems into thermal equilibrium.

What makes the finding significant is that this boundary is universal. No matter how much energy is applied or how strongly a system is manipulated, the process cannot be forced to go any faster.