PhD candidate in Nanoscience. Title: Nonlinear Casimir–Optomechanics on SOI Nanophotonic Cavities

Electronics and Biomedics Engineering Department

Organisation/Company Universitat de Barcelona Department Electronics and Biomedics Engineering Department Research Field Engineering Technology Physics Researcher Profile First Stage Researcher (R1) Positions PhD Positions Application Deadline 1 Nov 2026 - 17:00 (Europe/Madrid) Country Spain Type of Contract Temporary Job Status Full-time Hours Per Week 37,5 Offer Starting Date 1 Feb 2027 Is the job funded through the EU Research Framework Programme? Horizon Europe - MSCA Marie Curie Grant Agreement Number Is the Job related to staff position within a Research Infrastructure? No

The research project aims to investigate nonlinear mechanical and optomechanical phenomena in silicon-on-insulator nanophotonic cavities. In particular, the selected candidate will study how Casimir–Lifshitz forces modify the effective mechanical stiffness and nonlinear dynamics of nanostructures with nanometric gaps.

The work will combine the design, simulation and experimental characterization of optomechanical cavities, with particular emphasis on Casimir‑induced frequency shifts, Duffing nonlinearities, hysteresis, intermodulation and parametric amplification.

Responsibilities and main tasks

The doctoral candidate will:

• Design and investigate SOI photonic‑crystal and slot cavities; perform optical and radio‑frequency characterization; analyse nonlinear mechanical dynamics; and compare experimental measurements with Casimir‑gradient and spring‑modulation models.
• Contribute to the preparation of scientific publications, conference presentations, and project reports.
• Participate actively in the research activities and scientific meetings of the research group.

Scientific objectives

• Objective 1 – Low risk: Quantify Casimir‑induced stiffness in SOI photonic‑crystal and slot cavities and validate the optical readout for dynamic studies.
  Verifiable goal: Extract Casimir‑induced frequency shifts from thermal‑noise spectra and fit the experimental measurements to Casimir‑gradient models.
  
• Objective 2 – Medium risk: Map and exploit Casimir‑induced Duffing nonlinearity and intermodulation under strong optical driving.
  Verifiable goal: Measure amplitude‑dependent mechanical resonance and hysteresis, and extract the effective Duffing coefficient.
  
• Objective 3 – Higher risk: Realize Casimir‑assisted parametric amplification and dynamical coupling mediated by the optical field.
  Verifiable goal: Demonstrate parametric gain through modulation of the optical pump and map Arnold tongues consistent with a spring‑modulation model.

Secondments and network collaboration

The project includes two secondments that connect the Universitat de Barcelona research with complementary theoretical and industrial expertise:

• Danmarks Tekniske Universitet, to learn modal theory of nanomechanics and optical cavities.
• Lizard Photonics ApS, to learn basic fabrication methods and optical‑cavity design.

Research team

The project will be led by Daniel Navarro Urrios, with Jordi Gomis Brescó as a member of the research team.

Candidate profile

Applicants should hold a degree and a master’s qualification in Physics, Photonics, Nanoscience, Electronic Engineering or a related discipline and meet the requirements for admission to the Nanoscience doctoral programme at the University of Barcelona.

Previous experience in one or more of the following areas will be positively valued:

• Photonics or nanophotonics.
• Optomechanics or nanomechanics.
• Numerical simulations using COMSOL, Lumerical or related software.
• Optical laboratory techniques.
• Data analysis and scientific programming.

A good command of written and spoken English, motivation for experimental and theoretical research, and the ability to work in an interdisciplinary environment are also required.

Research Field Physics Education Level Master Degree or equivalent

Research Field Engineering Education Level Master Degree or equivalent

Skills/Qualifications

Hold a BSc/MSc in Physics, Photonics, Nanoscience, Electronic Engineering or a related discipline and fulfil the requirements to be admitted into the Nanoscience PhD program at the Universitat de Barcelona:

Due to the mobility rules of the Marie Skłodowska‑Curie program, you must not have resided or carried out your main activity (work, studies, etc.) in Spain for more than 12 months in the 36 months immediately before the recruitment date.

Languages ENGLISH Level Excellent

Languages SPANISH Level Basic

Languages CATALAN Level Basic

Additional