Welcome to the quantum optics lab

We explore fundamental quantum physics with atoms, photons and phonons and harness it for applications in quantum technology. In our experiments we study many-particle entanglement in Bose-Einstein condensates, explore hybrid atom-optomechanical systems, and develop quantum memories and sensors with atomic vapour cells. Our research combines experiment with theory, employing techniques of atomic physics, quantum optics and optomechanics. A common goal of our activities is to investigate quantum physics in systems of increasing size and complexity.

News from the lab

Microfabricated Rb Cell

Optical Memory in a Microfabricated Rubidium Vapor Cell

Scalable quantum technology can appear hopelessly out of reach when we envision having to replicate room-sized experiments full of complex machines. In our latest memory experiments we flip the script by demonstrating optical storage in a…
Entangled Bose-Einstein condensates

Einstein-Podolsky-Rosen Experiment with two Bose-Einstein condensates

We observed the Einstein-Podolsky-Rosen paradox with two spatially separated, massive many-particle systems. Our results show that the conflict between quantum mechanics and local realism does not disappear as the system size increases to…
Coherent Feedback Control

Optical Coherent Feedback Control of a Mechanical Oscillator

Coherent feedback is a kind of feedback that processes and feeds back quantum signals without measuring the system. We implemented a coherent feedback loop consisting of a light field interacting twice with the same mechanical mode of a…
The awardees Maryse Ernzer and Paolo Colciaghi

Maryse and Paolo Receive QCQT Excellence Awards

Congratulations to Maryse Ernzer and Paolo Colciaghi! Both of their 2022 research has been recognized with QCQT excellence awards.
Thomas Karg wins Swiss Nanotechnology PhD Award

Thomas Karg wins SPS Award

Each year, the Swiss Physical Society awards topical prizes for exceptional PhD thesis. We congratulate Thomas Karg on winning this year's Metrology award, sponsored by METAS, for his work on the strong coupling of a nanomechanical…
Single Photon Storage

Single-Photon Storage in a Ground-State Vapor Cell Quantum Memory

Storing single photons from solid state sources in hot atomic vapor has been a long standing challenge due to read-out noise produced by the atoms. With a storage scheme exploiting polarization selection rules we have succeded in storing…
Coherent Feedback Cooling

Coherent Feedback Cooling of a Nanomechanical Membrane with Atomic Spins

Coherent feedback stabilises a system towards a target state without the need of a measurement, thus avoiding the quantum backaction inherent to measurements. In our experiment, we employ optical coherent feedback to remotely cool a…
Thomas Karg wins Swiss Nanotechnology PhD Award

Thomas Karg wins Swiss Nanotechnology PhD Award

The Swiss Nanotechnology PhD Award is given by the Swiss Micro‐ and Nanotechnology Network for excellent scientific first‐author publications in the field of Nanotechnology and Nanoscience published by PhD students. Thomas Karg received the…
Light-mediated strong coupling

Light-mediated strong coupling between a mechanical oscillator and atomic spins one meter apart

Engineering strong Hamiltonian interactions between quantum systems is usually only possible over short distances. We demonstrate a new scheme for long-distance interactions mediated by light and use it for a range of experiments in hybrid…

Basel Quantum Metrology and Sensing Conference

The Basel Quantum Metrology and Sensing Conference (BQMS 2020) will highlight the state of the art and most recent advances in quantum sensing and quantum metrology with atomic and solid-state spin systems. It will gather key global players…