Semiconductor quantum dots are promising building blocks for quantum networks, offering bright, on-demand emission of single photons and entangled photon pairs together with strong light–matter coupling. However, generating high-quality quantum light is only the first step. Distributing entanglement across multiple network segments also requires an efficient spin–photon interface and a memory capable of preserving coherence while remote entanglement is being established. Moreover, conventional strictly resonant excitation requires stringent suppression of scattered laser light, typically through polarization filtering, limiting photon collection and experimental flexibility.

In this talk, I begin by presenting the first experimental demonstration of red-detuned coherent excitation of a quantum emitter using the SUPER (Swing-up of Quantum Emitter Population) scheme. SUPER is a coherent population-control method based on a red-detuned multicolor optical field, in contrast to conventional single-field resonant excitation. Using this approach, we demonstrated deterministic single-photon generation without polarization filtering and subsequently extended the method to generate biexciton–exciton cascade photon pairs from quantum dots with small fine-structure splitting, providing a promising route toward entangled-photon-pair generation. Following our initial demonstration, the SUPER scheme has attracted growing interest from research groups worldwide and has become an active direction in quantum-emitter research.

Open, tunable microcavities have achieved end-to-end photon efficiencies above 70% with InGaAs quantum dots, among the highest reported for quantum-dot sources. Here, we present what is, to our knowledge, the first open-cavity interface with GaAs quantum dots. The favorable electron-spin properties of GaAs quantum dots, arising from their nearly strain-free growth by droplet etching, make them particularly promising for quantum-repeater applications. Our preliminary results show clear Purcell enhancement, including shorter radiative lifetimes and increased photon-collection efficiency, important steps toward single-shot spin readout and high-fidelity time-bin entanglement between an electron spin and an emitted photon. The combination of high-quality photons, efficient collection, and coherent spin control is also promising for photonic cluster-state generation.

Finally, I discuss two ongoing research directions: developing cavity-enhanced single-shot spin readout and a longer-lived quantum memory and extending the SUPER scheme to cavity-based spin initialization and readout. Together with background-free single-photon and cascade-pair generation, these capabilities could enable an efficient spin–photon interface with integrated quantum memory, providing a solid-state pathway toward scalable quantum networks.

Yusuf Karli is a Research Fellow at Emmanuel College, University of Cambridge, where he works on quantum science using semiconductorquantum dots, with research spanning quantum networks, spin-photon entanglement, and many-body physics for quantum registers. He is also the coordinator of QTurkey (Quantum Türkiye), one of Türkiye’s largest non-profit quantum initiatives, with a presence across universities throughout the country and a focus on quantum science, education, and communication. As a fun fact, he helped host the travelling QuanTour quantum light source in Cambridge and later launched a social media campaign challenging the project to add Türkiye as its 13th destination, and it worked! :)

Generic quantum many-body systems are expected to thermalize, scrambling local information and coherent dynamics. Yet rare instances of nonthermal dynamics can persist in otherwise chaotic systems - a phenomenon known as weak ergodicity breaking. A paradigmatic example is quantum many-body scarring, in which special initial states exhibit long-lived coherent dynamics in the form of periodic revivals.

I will show that weak ergodicity breaking is considerably richer than previously known and present new forms of scarring that reveal the phenomenon to be more common than previously thought and, more importantly, demonstrate nonthermal dynamics beyond homogeneous revivals. Examples include chirally propagating quasiparticles that coherently transport information and energy, approximate topological edge physics, and other phenomena unexpected at high energy densities. An important mechanism underlying many of these phenomena is the presence of structured subspaces protected by destructive interference.

These results also frame a discussion of how to systematically discover novel nonthermal dynamics, whether weak ergodicity breaking can affect physical properties of the system, such as transport, and how their coherence might be harnessed for applications in quantum technologies.

The field of circuit quantum acoustodynamics (cQAD) involves microwave frequency mechanical resonators engineered to interact with superconducting qubits. Experiments in this field have made significant progress, demonstrating the viability of cQAD devices for applications in quantum information science. However, as experimental complexity grows, decoherence becomes increasingly challenging to evade, posing a problem for cQAD devices and more generally devices involving superconducting qubits. Here we present recent experimental results from a cQAD system involving a transmon qubit strongly coupled to a surface acoustic wave (SAW) resonator. We rely on the coherent qubit-SAW dynamics to characterize the decoherence of the SAW resonator, and then with the same device we can take advantage of the acoustic losses imparted on the qubit to perform a bath engineering experiment, using coherent drives to stabilize qubit states. Finally, we discuss experimental progress towards probing noise associated with two level system defects, which is a dominant noise source for superconducting qubit systems.

Two-dimensional moiré heterostructures have revealed a range of exotic correlated phases, including generalized Wigner crystals, orbital ferromagnetism, and the fractional quantum anomalous Hall effect. Far less is known about the interactions in Bose–Fermi mixtures and spinful Bose–Hubbard systems. I use a WSe₂/WS₂ heterobilayer, which hosts a triangular Hubbard lattice, to realize a strongly correlated Bose–Fermi system [1, 2]: interlayer excitons (bosons) coexisting with a correlated electron liquid (fermions), with independent control of the boson and fermion densities.

In the first part, I work with excitons in the extremely dilute limit and control their dynamics through the surrounding electronic order [1]. We observe pronounced modulation of exciton diffusion near the generalized Wigner crystals, and the formation of attractive polarons in the dilute Fermi sea. Near the Mott insulating state, rather than becoming trapped, excitons diffuse a thousandfold faster, revealing their transformation into non-monogamous excitons at the correlated insulator. We then exploit this understanding to achieve spin-selective control of exciton diffusion in an external magnetic field.

In the second part, we study a purely excitonic (bosonic) system at higher density, where strong interactions dominate the dynamics. Our spatiotemporal measurements show that excitons interact strongly and acquire spin-dependent diffusion in the presence of a magnetic field, forming a nonequilibrium state in which opposite-spin excitons spatially separate into exciton spin clusters [3].

Together, these results establish exciton dynamics as a sensitive readout of correlated order and a route to nonequilibrium many-body states. I close with a future direction where we reshape the system in situ, using the correlated electrons as a reconfigurable lattice.

[1] P. Upadhyay et al., Science 391,394-398 (2026).

[2] B. Gao et al., Nat Commun 15, 2305 (2024).

[3] P. Upadhyay et al., manuscript in preparation.

Pranshoo is a PhD student at the Joint Quantum Institute, UMD where he steers the many-body interactions wihtin quantum matter with light. Away from the lab, he steers the interactions between people with music and dance.