“Updates to the Second Law from Quantum Thermodynamics”

Nicole Yunger Halpern

Abstract: Thermodynamics reigns as queen of the physical theories, governing everything from biophysics to cosmology. The second law of thermodynamics heads her court, stipulating that time appears to flow in only one direction and limiting engines’ efficiencies. However, idealizations curtail the original second law’s applicability: small systems violate simple, early formulations of the law, which imply quantitative predictions only about equilibrium states. The nineteenth-century law has been tightened, including within quantum thermodynamics, a field that has taken off in the past decade. I will illustrate this progress with examples. As a spoiler alert: I know of no ways to leverage quantum phenomena to break the second law. However, quantum and other resources enable us to “bend around” the second law: we can appear to violate the law while, in fact, subtly avoiding assumptions behind modern formulations of the law.