Event Type: Seminar

Matrix product states for emitters in an SSH cavity array Collective light-matter effects such as superradiance and subradiance are well understood for emitters coupled to a Markovian bath. For more complex, structured baths, such as an SSH-like cavity chain, the existence and behavior of these many-excitation effects has remained largely […]

Efficient coherent control and multi-directional release of quantum information are two key challenges to be addressed by any platform eligible for distributed quantum devices. In context of circuit and waveguide quantum electrodynamics, such challenges have to be addressed by developing systems of artificial atoms interconnected through microwave waveguides, working as […]

We implement a gate-tunable transmon (gatemon) qubit based on an InAs nanowire Josephson junction and identify distinct features in its microwave spectra that provide clear evidence of ultrastrong light–matter hybridization with a probing resonator [1]. These signatures include deviations of the measured anticrossing from the predictions of the Jaynes–Cummings model. […]

The laser stands as one of the most iconic examples of macroscopic coherence, fundamentally reshaping our understanding of light-matter interaction and underpinning key technologies of modern science. Yet lasing action is not exclusive to light: in principle, it can emerge in any bosonic system. The concept of the phonon laser, […]

In this seminar, I will talk about our recent results published in “Fibonacci Waveguide Quantum Electrodynamics. F. Bönsel, F. K. Kunst, F. Roccati. Quantum 10, 2081 (2026)” and “Atom-Photon Bound States in Fractal Photonic Lattices: Localization Length and Anomalous Diffusion. F. Bönsel, F. K. Kunst, F. Roccati. arXiv:2605.23625 “

Radiative coupling between quantum emitters leads to a range of spectacular emission phenomena such as super- and subradiance. Waveguide quantum electrodynamics (QED) allows the coupling of spatially separated emitters, while preserving individual addressability. I will present our work with a pair of independently tunable solid-state quantum dots (QDs) embedded in […]

Large Fock states are key nonclassical resources for bosonic quantum information, quantum-enhanced metrology, and the exploration of nonclassical dynamics in harmonic oscillators. However, preparing them high success probability remains challenging: deterministic protocols become increasingly control-intensive at large excitation number, while measurement-based strategies are naturally robust but suffer from rapidly decreasing […]

I will present experimental studies of one and two photon transitions in an array of Cs atoms trapped with a lattice of evanescent fields around an optical nanofiber, a waveguide. The transitions involved in the experiment are 6S1/2, 6P3/2 and 6D5/2. The single atom absorption is about 0.5% on the […]

We design a universal framework for fermionic quantum hardware that runs efficient variational algorithms to simulate generic many-body systems beyond the hardware’s native interactions. Our analysis shows that one can quantum simulate the ground-state properties of a broad class of gapless target Hamiltonians of local observables in a quantum evolution […]

In this talk, I would like to present our results on the interactions of quantum emitters coupled to the boundary of a two-dimensional photonic graphene. While 2D topological lattices typically support propagating edge modes, a zigzag termination in this system hosts a unique set of dispersionless, non-propagating edge modes that […]