Hot quantum systems can cool faster than their colder analogues. This identification adds depth to such a phenomenon as the effect of Mpemba.
What is the effect of a mpemba?
The MPEmbA effect is an illogical phenomenon in which hot water can freeze faster than cold water under certain conditions. The phenomenon was named after the Tanzani student Erasto Mpemba, who noticed him in the 1960s and attracted the attention of the scientific community to this issue. Although interest in the phenomenon has existed for centuries (Aristotle may have been the first to pay attention to it), the exact cause of the effect of Mpemba still causes discussions among scientists.
New discoveries
A team of researchers from Kyoto University and Tokyo University of Agricultural and Technological Sciences discovered that the quantum effect Mpemba in temperature can manifest itself in a wide range of initial conditions. “The quantum effect of Mpemba retains the memory of the initial conditions, which leads to abnormal thermal relaxation in the following time,” – comments the project manager Hisao Hayakava.
For the experiment, the team prepared two systems with quantum points connected to a thermal bath. Both systems were cooled to a low-temperature equilibrium state, which made it possible to monitor their temporary evolution. “When two copies crossed each other to reached the same equilibrium state, we realized that we have reached the thermal quantum effect of Mpemba,” the co-author Satoshi Takada emphasizes.
Prospects for the future
“Our results encourage us to look for the potential application of the quantum effect of Mpemba in future applications that go beyond thermal tests,” said Hayakawa.