Natasha Tomm

Surface passivation of GaAs mitigates surface-related losses in a microcavity

We found that GaAs surface passivation is key to minimize losses in a gated semiconductor microcavity and thus increase its quality factor by almost two orders of magnitude. The procedure not only eliminates a Franz-Keldysh-like surface loss inherent to gated semiconductor microcavities, but also mitigates the effect of surface scattering due to roughness. We elucidate

QSIT features Nadine Leisgang in #NCCRWomen 2021 campaign

Nadine Leisgang was featured by NCCR (National Centres of Competence in Research) in their new campaign #NCCRWomen. In the video, Nadine explains a bit about her work as a physicist at the University of Basel and her motivation to do science. Congratulations! Read more here: https://nccr-qsit.ethz.ch/equal-opportunity/NCCRWomen_campaign.html Video here: https://www.youtube.com/watch?v=3eaSz3fry84  

A record-breaking single photon source

In our recent publication in Nature Nanotechnology we present the results of our record-breaking single photon source. The source, based on InAs quantum dots coupled in a carefully designed open-access microcavity, is able to emit up to 1 billion single photons per second with an end-to-end efficiency of 57%. Furthermore, photons present high single-photon purity

Interlayer excitons in bilayer MoS2

In our recent paper, we have shown that interlayer excitons in bilayer MoS2 exhibit both a high oscillator strength and highly tunable energies in an applied electric field. Owing to this very large tunability, we were able to optically probe the interaction between intra- and interlayer excitons as they were energetically tuned into resonance. These

Daniel Najer wins the Swiss Nanotechnology PhD award!

Daniel Najer was one of the 5 young scientists to win the Swiss Nanotechnology PhD award. The prize is awarded by the company Bühler for Daniel’s publication on an efficient light-matter interface, coupling a semiconductor QD strongly to an optical microcavity. Congratulations! Read more here: https://nanoscience.ch/en/2020/07/15/five-awards-for-young-scientists/ 

Strong-coupling of a semiconductor quantum dot in a microcavity

A coherent exchange of a single energy quantum between an “atom” (in our case a gated InAs quantum dot) and an optical cavity has been reported by our group in Nature. We achieve an atom-cavity Cooperativity of 150, and probe the transitions between singly and doubly excited photon-atom system using photon-statistics spectroscopy.

Tomek secures Marie-Skłodowska-Curie Fellowship

Our Post-doctoral research, Tomek, has been awarded a Marie-Skłdowska-Curie Individual Fellowship! Tomek’s project, entitled “High-Frequency Spin Entanglement Generation in Diamond” (Hi-FrED) aims at establishing the Nitrogen-Vacancy center in diamond not only as spin-coherent, but also as an optically-coherent efficient emitter of single photons. More details about the project, starting in September 2019, can be found

Hi-FRED Project

Host: Prof. Dr. Richard J. Warburton, in collaboration with the Quantum Sensing group (prof. Patrick Maletinsky) and the Nano-phononics group (prof. Ilaria Zardo) Fellow: Dr. Tomasz Jakubczyk Core participants: Viktoria Yurgens, Sigurd Flågan, Brendan Shields The ultimate goal of the project is to achieve high-frequency generation of spin-spin entanglement in spatially separated nitrogen vacancy (NV)