Gianluca Rastelli - Pitaevskii Center on Bose-Einstein Condensation, CNR-INO and Dipartimento di Fisica dell’Universitá di Trento

Circuit Quantum Electrodynamics with Semiconductor Quantum Dots

Circuit quantum electrodynamics (circuit QED) advanced thanks to the development of the field of quantum circuit which find applications not only as quantum bits for quantum information processing but also in the linear and nonlinear manipulation of quantum microwave fields. Circuit QED with quantum dots (QDs) is a platform where QDs act as artificial atoms that interact with microwave photons in superconducting circuits, enabling the study of light-matter interaction at the quantum level.

After providing an overview of the field, I will present theoretical proposals for generating entangled photons and detecting single microwave photons by utilizing coherent nanoconductors as quantum sources and detectors, harnessing the unique properties of superconducting and semiconducting nanostructures in combination with microwave quantum devices.

In a first work [1], we explore a proposal to transfer entanglement from a many-body quantum condensate—specifically, a BCS superconductor—to microwave photons propagating in transmission lines. We demonstrate the potential to generate pairs of frequency-entangled photons from electrons emitted by a superconducting nanoscale quantum device known as a “Cooper pair splitter.”

In a second work [2], we study quantum dots dispersively coupled to a microwave resonant cavity, enabling non-absorptive detection of individual itinerant microwave photons.

In the third work [3], we investigate how a single microwave photon can drastically affect electron transport interference in a system of two parallel quantum dots.

[1] M. Governale, C. Schönenberger, P. Scarlino, and G. Rastelli, 

“Entangled Photon-Pair Emission in Waveguide Circuit QED from a Cooper Pair Splitter”,

PRX Quantum 6, 020339 (2025),

https://physics.aps.org/articles/v18/s70 (Physics Magazine).

[2] S. Matern, A. Biella, P. Scarlino, I. Carusotto, G. Rastelli, 

""Dispersive detection of single microwave photons with quantum dots"",

https://arxiv.org/abs/2511.19128.

[3] S. Matern, A. Biella, P. Scarlino, I. Carusotto, G. Rastelli, 

""Microwave photons detection via quantum interference in electron transport"",

(in preparation).