Postdoctoral Researcher

Institute of High Pressure Physics PAS; Warszawa; On-site; PLN 102,000 - 122,000; Full time

Benefits offered by this job

Conference budget for international/夏r

Job summary

Institute of High Pressure Physics PAS in Warsaw seeks a post-doctoral researcher for a project on machine learning aided tunable-filter THz spectroscopy. The role focuses on theoretical electromagnetic modelling of AlGaN/GaN metasurface structures using COMSOL, aiming to optimize a filter that maximizes spectral information encoded by the detector signal.

The position is largely computational, with fabrication and testing of chosen structures possible in our labs.

Qualifications

• PhD in physics, mathematics, CS, electronics, or related field; eligible to start.
• PhD from IHPP PAS avoided unless internship path met.
• Experience in numerical electromagnetic modelling.
• Solid-state physics basics incl. electrodynamics of semiconductor structures.
• Fluent English for literature comprehension and presenting results.

Responsibilities

• Design and optimise metallic filter metasurfaces using FEM in COMSOL.
• Validate theoretical models against experimental data.
• Conduct temperature-dependent simulations for resonance stability.
• Collaborate with fabrication team to translate designs into specifications.
• Optional participation in fabrication and measurements of designed structures.

Skills

Fluent English

Numerical EM modelling

Solid-state physics basics

Education

Ph.D. in physics, mathematics, CS, electronics, or related field

Tools

Python

COMSOL Multiphysics

Finite Element Method

MATLAB

Job description

Post-doc position in the project "Machine learning aided approach to the new type tunable-filter-based computational THz spectroscopy"

Terahertz spectroscopy gives access to material-specific low-energy excitations without destroying the sample. However, THz spectrometers remain complex and expensive, as they typically rely on interferometry or time-domain sampling. In this project we investigate an alternative measurement approach: an electrically tunable plasmonic filter encodes the spectrum of the incident radiation, a detector records the transmitted signal across a range of gate voltages, followed by computational reconstruction of the spectrum. With no moving elements and no femtosecond laser source, the instrument becomes simpler, smaller and more robust. Filter-based computational spectroscopy has attracted considerable interest, but a full experimental demonstration in the terahertz band is still missing. As the tunable filter, we propose AlGaN/GaN heterostructures with a grating gate, which exhibit electrically tunable plasmonic resonances in the THz range and are fabricated and investigated in the principal investigator's group.

The main task in the post-doc position will be theoretical electromagnetic modelling for this class of structures. The goal is to design an optimal filter: to select a metasurface geometry that maximizes the spectral information encoded in the measurement. This conditions the reconstruction of the spectrum from the detector signal, and thereby sets the limit on the achievable resolution. Since the material platform determines the spectral range attainable in a future device, the modelling will focus on AlGaN/GaN, with the possibility of extending it to other platforms, such as graphene or HgCdTe.

The position is mostly computational, but the selected optimised structures will be fabricated and characterised in our laboratories, offering the opportunity to take part in that stage as well.

Key responsibilities

• Design and optimisation of metallic filter metasurfaces (grating gates, split-ring resonators and similar) patterned on two-dimensional electron systems, using the Finite Element Method in COMSOL Multiphysics, accounting for their electrical modulation.
• Validation of theoretical models results with the experimental data.
• Temperature-dependent simulations to assess the thermal stability of the resonances.
• Cooperation with the fabrication team in translating optimised designs into manufacturing specifications.
• (Optional) Participation in the fabrication and measurement of the designed structures.

Requirements

• A Ph.D. degree in physics, mathematics, computer science, electronics, materials engineering or a related field, allowing the candidate to start a post-doc position. The degree must be obtained at the latest on the day of signing the employment contract and no earlier than within 12 years before 1 January of the year of employment in the project (for employment planned in 2026 - no earlier than 1 January 2014). This period is extended by career breaks as defined for post-doc positions in the NCN Regulations (long-term sick leave and rehabilitation benefits, leave related to the care and upbringing of children, and in the case of women - 18 months for each child born or adopted).
• The Ph.D. degree must have been awarded by an institution other than IHPP PAS. Alternatively, the candidate must have completed a continuous, documented research internship of at least 9 months (undertaken during doctoral school, doctoral studies, or after the award of the Ph.D. degree) at an institution other than IHPP PAS and in a country other than the country in which the degree was obtained.
• Experience in numerical electromagnetic modelling (finite element, finite difference, integral equation or equivalent methods).
• Understanding of the basics of solid state physics, including the electrodynamics of semiconductor structures.
• Python programming skills (or experience with a similar language, e. g. MATLAB) at a level allowing data preparation, analysis, and processing of results from both calculations and experiments.
• Fluent English, sufficient for understanding scientific literature and for presenting and discussing results.

Additional assets

• Proficiency in COMSOL Multiphysics, envisaged as the main computational tool for this position.
• Experience in automating calculations.
• Hands‑on experience with THz measurements (FTIR‑THz, THz‑TDS, cryogenic characterisation).
• Experience with plasmonic crystals and two‑dimensional electron systems (AlGaN/GaN, GaAs/AlGaAs, graphene), in particular with grating‑gate structures.
• Experience in the fabrication of AlGaN/GaN or related semiconductor heterostructures.
• Experience in metasurface fabrication, e. g. by laser writing or electron beam lithography

Terms of employment

Starting date: preferably right after the recruitment process is completed.

Duration: 24 months.

Remuneration: estimated net salary approximately PLN 10,000 (ca. EUR 2,350).

Form of employment: employment contract, full-time position.

Place of work: Warsaw,on‑site at the Centre for Advanced Materials and Technologies CEZAMAT, Warsaw University of Technology, Poleczki 19, where the project team is based. Part of the technological work is carried out at the IHPP PAS site at Sokołowska 29/37.

Conferences: a budget for participation in international conferences and summer schools.

NCN regulations: during the period of receiving this remuneration, the employee may not receive any other remuneration from funds allocated as direct costs of research projects funded under NCN calls, any remuneration from another employer under an employment contract (including employers based outside Poland), or retirement benefits or equivalent, in Poland or abroad.

Required documents

• CV with contact details;
• Motivation letter with particular emphasis on the candidate’s experience, motivation and aspects related to this project.
• At least 2 recommendation letters from senior researchers familiar with the candidate's work.
• List of scientific achievements and publications.
• A copy of Ph.D. diploma (or a signed attestation that the candidate will obtain the Ph.D. degree at the latest on the day of signing the employment contract, with the information about the discipline).
• Signed personal data processing statement (wording below).

Personal data processing statement

To allow us to process your data, please include the following signed statement in your application:

I hereby consent to have my personal data processed by the Institute of High Pressure Physics of the Polish Academy of Sciences with its registered office at Sokolowska 29/37, 01-142 Warsaw, Poland for the purpose of carrying out a recruitment process and selecting an employee and concluding a contract for employment at the Institute of High Pressure Physics of the Polish Academy of Sciences. I have been informed of my rights and duties. I understand that provision of my personal data is voluntary.