title: Discrete four-stroke quantum heat engine exploring the origin of friction.
abstract: The optimal power performance of a first-principle quantum heat engine model shows friction-like phenomena when the internal fluid Hamiltonian does not commute with the external control field. The model is based on interacting two-level systems where the external magnetic field serves as a control variable.
authors.affiliation: Department of Physical Chemistry, The Hebrew University, Jerusalem 91904, Israel.
authors.forename: Ronnie
authors.initials: R
authors.lastname: Kosloff
authors.forename: Tova
authors.initials: T
authors.lastname: Feldmann