A Bristol researcher, in collaboration with a physicist from Valencia, Spain, has established a novel thermodynamic method to test quantum advantages, which are central to quantum science and technologies. This has been jointly published in Physical Review Letters and Physical Review A.
In the recent joint publications Physical Review Letters and Physical Review A for APS, School of Physics Leverhulme Trust Early Career Fellow, Dr. Chung-Yun Hsieh, and collaborator at the University of Valencia (Spain), Prof. Manuel Gessner, have jointly developed the first thermodynamic method to universally certify quantum effects and their advantages.
Quantum physics gives access to features that can be harnessed in new technologies and in counterintuitive protocols with no classical counterpart. Entanglement, for example, enables quantum teleportation and measurements with precision beyond classical limits. On the other hand, stronger forms of quantum correlation can support highly secure communication. These useful features are known as quantum resources. Identifying advantages that cannot be achieved by classical means and can only be attained by utilising quantum resources, the so-called quantum advantages, is one of the central goals of quantum information science. Consequently, a major challenge is to verify the presence of quantum resources and determine the strength of advantages they can provide.
Until now, these tests have usually been designed separately for each resource and can differ drastically from one case to another. In recent work, Chung-Yun and Manuel show that a single family of energy-extraction tests can reveal and even characterise virtually any quantum resource satisfying minimal physical assumptions. These tests compare how much useful energy can be extracted before and after the system’s possible energy levels are changed in a controlled way. Chung-Yun and Manuel prove that extracted energies from these tests can completely characterise quantum resources. This not only directly implies the ability to reveal quantum resources, but also, rather strikingly, suggests that locally extracted energy can reveal entanglement shared between distant parties even when one side of the experiment is not trusted. These findings establish energy extraction as a universal tool for identifying and comparing quantum features behind emerging technologies.
