Experimental inhibition of decoherence on flying qubits via bang-bang control

TL;DR

This paper demonstrates that bang-bang control effectively suppresses polarization decoherence in flying qubits within optical ring cavities, extending a technique from nuclear spin systems to photonic quantum information processing.

Contribution

It introduces the application of bang-bang control to flying photonic qubits, showing its effectiveness in reducing decoherence in optical systems.

Findings

Decoherence of polarization states can be significantly reduced.

Bang-bang control extends to optical quantum information processes.

Experimental results confirm improved coherence times.

Abstract

Decoherence may significantly affect the polarization state of optical pulses propagating in dispersive media because of the unavoidable presence of more than a single frequency in the envelope of the pulse. Here we report on the suppression of polarization decoherence in a ring cavity obtained by properly retooling for photonic qubits the ``bang-bang'' protection technique already employed for nuclear spins and nuclear-quadrupole qubits. Our results show that bang-bang control can be profitably extended to quantum information processes involving flying polarization qubits.