PhD Studentship: Ultrafast Optical Switching in Plasmonic Gaps

This PhD project investigates ultrafast optical switching in plasmonic nanogaps, leveraging their exceptional ability to confine electromagnetic fields into sub-nanometer volumes [1-5]. Plasmonic nanogaps at atomic scale create extreme optical hotspots that enhance light-matter interactions, making them ideal for achieving low-energy, high-speed optical switching.

The research will focus on developing optical setup to achieve controlled ultrafast switching driven by intense femtosecond laser pulses. The project will explore how localized plasmonic fields modulate the electronic and vibrational states of molecules or quantum materials embedded in the gaps, enabling all-optical or optoelectronic switching. Special emphasis will be placed on understanding the dynamics of non-linear optical effects, such as multi-photon absorption and hot-electron generation, and their role in switching mechanisms.

Time-resolved spectroscopy, including pump-probe techniques, will be employed to measure sub-picosecond response times and elucidate the energy transfer pathways within the nanogap. Additionally, the research will investigate the temperature and material-dependent properties to optimize switching efficiency and stability.

This project aims to develop energy-efficient optical switches for next-generation photonic circuits and quantum technologies, offering transformative capabilities in high-speed data processing and nanoscale optoelectronics.

Applicants should have completed (or closer to completion) their undergraduate degree in Physics, Material Science, Physical Chemistry or related Physical Sciences (preferably with first-class honours or equivalent). Strong analytical and experimental skills are desirable. The project's specifics will be determined in collaboration with the successful candidate, tailoring the research to their interests.

The project will be conducted within the research group led by Dr. Rohit Chikkaraddy (https://www.birmingham.ac.uk/staff/profiles/physics/chikkaraddy-rohit.aspx), based at the Metamaterials and Nanophotonics Research Centre (https://www.birmingham.ac.uk/research/activity/physics/quantum/metamaterials/index.aspx) in the School of Physics and Astronomy at the University of Birmingham, UK.

The University is actively committed to promoting equality, diversity and inclusion and encourages applicants from all sections of society. In line with the Department’s Athena SWAN programme, we particularly encourage female candidates to apply.

Funding, awarded on a competitive basis, is available to UK/EU nationals, covering tuition fees and providing a living stipend for 3.5 years. Non-EU candidates with the appropriate qualifications will be considered.

Apply online via the above ‘Apply’ button and clearly specify the project's title, the name of the supervisor (Dr. Rohit Chikkaraddy), and the Metamaterials and Nanophotonics Research Centre. The application deadline is January 10, 2025.

For information on available funding, application guidance, or any other informal inquiries, please contact Dr. Rohit Chikkaraddy at r.chikkaraddy@bham.ac.uk. 

References:

[1] R. Chikkaraddy, et al. "Single-molecule mid-infrared spectroscopy and detection through vibrationally assisted luminescence", Nat. Photon. 17, 865–871 (2023).

[2] R. Chikkaraddy, et al. "Mid-infrared-perturbed molecular vibrational signatures in plasmonic nanocavities". Light: Science & Applications, 11, 19 (2022).

[3] A. Xomalis, X. Zheng, R. Chikkaraddy, et al. "Detecting mid-infrared light by molecular frequency upconversion in dual-wavelength nanoantennas". Science, 374, 1268 (2021).

[4] R. Chikkaraddy, et al. "Single-molecule strong coupling at room temperature in plasmonic nanocavities", Nature, 535, 127, (2016).

[5] R. Chikkaraddy, Single molecule ready to couple. Nat. Phys. 20, 694–695 (2024).

Advert information