Quantum Switch Rewrites Heat Flow by Scrambling Cause and Effect
Researchers used a quantum switch to create indefinite causal order between two heat reservoirs, effectively allowing heat to move from cooler to warmer regions and challenging a straightforward interpretation of the second law; an optical experiment with split photon beams matched theoretical predictions with over 99% fidelity, highlighting a potential bridge between quantum and classical causality and possible future photonics applications.
