Quantum Optics Seminar: Prof. Dr. Peter Rabl

Autonomous entanglement distribution in squeezed and thermal reservoirs 

In this talk, I will discuss the autonomous distribution of entanglement in quantum networks of qubits driven by squeezed or thermal light. In the first part, I will review some of our previous work on generating two-qubit as well as multi-qubit entangled states in a dual-rail waveguide QED system [1] by simply driving the qubits with a two-mode squeezed photon source and I will present some of the first experimental demonstrations of this scheme with superconducting circuits [2]. In the second part, I will then show that even a purely thermal photon source can generate highly entangled states between two spatially separated qubits, provided the photonic reservoir is sufficiently narrow-band, i.e., strongly non-Markovian [3]. I will explain the underlying mechanisms that lead to this surprising effect and discuss how it could potentially be used as a purely passive scheme to entangle superconducting qubits via room-temperature Johnson–Nyquist noise.