Breaking the quantum adiabatic speed limit by jumping along geodesics

TL;DR

This paper experimentally demonstrates that quantum adiabatic evolution can be achieved rapidly even with vanishing energy gaps by modulating dynamic phases, challenging traditional adiabatic speed limits.

Contribution

It verifies a new quantum adiabatic theorem and shows how to surpass traditional speed constraints in quantum evolutions through phase modulation.

Findings

Successful experimental demonstration with nitrogen-vacancy centers

Near-unit-fidelity adiabatic processes in finite times

Validation of the new quantum adiabatic theorem

Abstract

Quantum adiabatic evolutions find a broad range of applications in quantum physics and quantum technologies. The traditional form of the quantum adiabatic theorem limits the speed of adiabatic evolution by the minimum energy gaps of the system Hamiltonian. Here, we experimentally show using a nitrogen-vacancy center in diamond that, even in the presence of vanishing energy gaps, quantum adiabatic evolution is possible. This verifies a recently derived necessary and sufficient quantum adiabatic theorem and offers paths to overcome the conventionally assumed constraints on adiabatic methods. By fast modulation of dynamic phases, we demonstrate near-unit-fidelity quantum adiabatic processes in finite times. These results challenge traditional views and provide deeper understanding on quantum adiabatic processes, as well as promising strategies for the control of quantum systems.