Postdoctoral Researcher Position Available in Dielectric Surface Engineering for Quantum Sensors

The Spin Physics Group led by Prof. Christian Degen and Dr. Alexander Eichler is looking for a highly motivated postdoctoral researcher with a background in surface chemistry, characterization, and engineering, and with a broad interest in applications for quantum sensing.

Do you have experience in, or are willing to learn about, quantum metrology, optomechanics, magnetism, radio-frequency electronics, laser optics, and digital signal analysis? Are you persevering, independent, and a good team player? Get in touch with us!

The last two decades have seen a dramatic improvement in the fabrication and performance of nano- and micromechanical resonators. In particular, the quality factor (Q) of nanomechanical silicon nitride (SiN) resonators has been improved over five orders of magnitude, reaching values beyond one billion at room temperature. However, this drastic improvement of Q has been solely based on device design optimization. The actual underlying dissipation that is diluted has not been investigated in detail and has not seen any improvements.

Surface states, be it spins, electrical states, or crystal lattice defects, are considered a prime source for decoherence and dissipation in a wide range of contemporary quantum devices and can limit the quality factors of nanomechanical SiN resonators as well. The main aim of this work is to gain a better understanding of the remaining damping mechanisms in SiN resonators and to improve their Q by another order of magnitude through surface chemistry: an untapped, bottom-up approach to mitigate surface dissipation. The applications of these chemically functionalized membrane resonators are quantum-limited operation of membrane-based atomic force microscopy, magnetic resonance imaging, and mass sensors at the single-molecule regime.

The primary tasks for the position will focus on merging surface chemistry and engineering with state-of-the-art quantum cavity optomechanics and ultrasensitive force microscopy to improve the quality factors and chemical versatility of nanomechanical SiN resonators. You will explore various SiN surface modifications that maximize instrument performance by manipulating mechanical energy dissipation, eliminating surface defects, and controlling electronic contributions from self-assembled molecular films.

Similar surface functionalization strategies can be used in order to mitigate surface noise sources of decoherence in other quantum device architectures, e.g., diamond materials hosting near-surface nitrogen– vacancy (NV) centers, which is another core research area in our group. Thus, secondary tasks for the position will include applying surface termination and chemical modification to diamond materials and having the opportunity in parallel to support and to participate in PhD projects geared toward quantum sensing with NV centers. These areas include the development of improved surface engineering techniques that simultaneously stabilize shallow NV centers while enabling chemical functionalization for surface nuclear and electronic spin sensing of molecular adsorbates.

The anticipated start date is early 2024. 

• PhD degree in Physics, Physical Chemistry, Materials Science & Engineering, or similar
• Experience in chemical surface functionalization & characterization (i.e., XPS, UPS, scanning probe microscopy)
• Background in the field of quantum sensing, nanomechanics, magnetic sensors, or other magnetic systems
• Excellent interpersonal communication, teamwork & organizational skills
• Strong oral & written communication skills in English

ETH Zurich is a family-friendly employer with excellent working conditions. You can look forward to an exciting working environment, cultural diversity and attractive offers and benefits.