A Two-Qubit Engine Powered By Entanglement and Local Measurements

(Phys.org) Researchers at Institut Néel-CNRS, University of Saint Louis and University of Rochester recently realized a two-qubit engine fueled by entanglement and local measurements. The findings could open up exciting possibilities for thermodynamics research and inform the development of new quantum technologies.
A few years ago, Auffèves and some of her colleagues at Institut Néel-CNRS introduced the proof of concept for a measurement-fueled engine based on a single qubit. This was the first of a series of proposals that revealed the energetic counterpart of measurement devices.
So far, measurement processes were typically modeled using classical theoretical approaches. In their new paper, the researchers took a bold step forward by opening ‘the black box’ of measuring devices and looking at it from a quantum physics perspective.
In their study, Auffeves and her colleagues thus focused on so-called ‘composite systems.” Their analysis ultimately led to the design of a measurement-powered engine based on entangled qubits. In addition to local measurements, this engine is fueled by a physical phenomenon known as quantum entanglement.
The new engine proposed by the researchers has two qubits. A qubit is a quantum system with two energy states: the ground state |0> and the excited state |1>.
“Our results shed new light on the measurement postulate in quantum mechanics,” Auffèves said. “Since this mechanism still feeds fundamental debates, one can hope that quantum energetics provides new measurable quantities to distinguish between the various interpretations of quantum mechanics. On a more applied side, the energetic footprints of quantum measurement and entanglement will have an impact on the energy cost of quantum technologies and their potential for scalability.”