Fundamental quantum theorem now holds for finite temperatures and not just absolute zero

Absolute zero—the most appropriate temperature for both quantum experiments and quantum computing—makes it easier to describe a system by relying on a set of fundamental propositions. One of them, the quantum adiabatic theorem, ensures simpler dynamics of quantum systems if external parameters change smoothly enough. Since absolute zero is physically unreachable, broadening the range of theoretical research tools for finite temperatures is a highly topical issue. A team of Russian physicists has made an important step forward in this direction by proving the adiabatic theorem at a finite temperature and identifying quantitative conditions for adiabatic dynamics. Their findings will be of high interest for developers of next-generation quantum devices that require fine-tuning of the properties of quantum superpositions involving hundreds or thousands of elements. This research was published in Physical Review A.