3 papers
quant-ph2026
Imaginarity as a necessary resource for trainability in QAOA
Syed Muhammad Ali Hassan, Kostas Blekos, Stefan Kühn +2
The quantum approximate optimization algorithm (QAOA) tackles combinatorial problems by tuning a quantum circuit in a classical loop, often guided by gradients. We show that the gr…
quant-ph2024
The gravitational quantum Otto refrigeration cycle
Nikos K. Kollas
We take advantage of the gravitational redshift experienced by a photon propagating in curved spacetime in order to construct a quantum Otto refrigeration cycle. Deriving a lower b…
quant-ph2023
An exactly solvable relativistic quantum Otto engine
Nikos K. Kollas, Dimitris Moustos
We revisit the mathematics of exactly solvable Unruh-DeWitt detector models, interacting with massless scalar fields under instantaneous interactions, to construct a relativistic q…