Phys.org April 26, 2021
As an immediate consequence of the effect of quantum mechanics, the measuring device provides both energy and entropy to the quantum system. Previously an international team of researchers (France, USA – University of Rochester, Washington University, Chapman University) introduced the proof of concept for a measurement-fueled engine based on a single qubit. Now they have introduced a two-qubit engine that is powered by entanglement and local measurements. Energy is extracted from the detuned qubits coherently exchanging a single excitation. Generalizing to an N-qubit chain, they showed that the low energy of the first qubit can be up-converted to an arbitrarily high energy at the last qubit by successive neighbor swap operations and local measurements. They finally modeled the local measurement as the entanglement of a qubit with a meter, and they identified the fuel as the energetic cost to erase the correlations between the qubits. The findings extend measurement-powered engines to composite working substances and provide a microscopic interpretation of the fueling mechanism…read more. TECHNICAL ARTICLEÂ
A two-bit engine…Credit: Phys. Rev. Lett. 126, 120605, 24 March 2021.Â