Colloquia

Superconducting circuits can be used as artificial atoms and we will discuss how they can be used to study new physics. Specifically, I will show how artificial atoms can be used to study vacuum fluctuations by placing the atom in front of a mirror. [more]

The talk reviews the recent works of the Laser Physics Group at NTNU on femtosecond waveguide lasers operating in the mid-IR wavelength range above 2 microns, as well as the implications this class of lasers may have for real-world applications and for future research, including quantum technologies. Recent progress in Cr²⁺:ZnS waveguides demonstrates laser amplification, frequency comb generation, and nonlinear conversion, targeting a miniaturized, ultra-stable comb spanning visible (<600 nm) to mid-IR (>5 μm) with intrinsic support for f–2f, 2f–3f, and related stabilization schemes. This requires balancing mode quality, amplification, and spectral broadening. [more]

In optics, vortices appear as phase twists of the electromagnetic field, traditionally arising from interactions between light and matter. Our lab investigates an extreme regime of optical nonlinearity in which quantum vortices emerge from strong, effective interactions between individual photons. We observe structured phase singularities in the few-photon wavefunction, including vortex lines and rings forming inside the optical medium. [more]

Quantum information technology is advancing at an astonishing pace. What should we do with it? In this colloquium, I will argue that one of the most powerful and near-term applications of quantum computers lies in quantum sensing. We will show how a digital quantum computer can be used to improve a foundational sensing task: the detection of weak oscillating fields with unknown amplitude and frequency. This task underlies a wide range of real-world applications, from NMR and atomic clocks to gravitational-wave detection and dark-matter searches. [more]

Double feature of M.Sc. Irene Prieto-Rodríguez & Dr. Liyang Qiu [more]