Dr J Mol
Applications accepted all year round
Funded PhD Project (UK Students Only)
About the Project
Single-electron quantum devices have potential use as radiation sensors for fundamental and applied science applications. We propose to develop arrays of graphene-based single-electron transistors that operate from deep cryogenic temperatures towards room temperature. Graphene single electron transistors operating at millikelvin temperature have already been demonstrated to be ultra-sensitive THz detectors, and single-electron quantum devices are being considered for possible dark matter experiments. In these experiments radiation deposited in the substrate is converted into phonons and charge that are then detected by the quantum devices.
The aim of this project is to replace conventional (organic) semiconductor field-effect transistors with single-electron transistors as radiation sensors. Single-electron transistors are quantum-limited electrometers with sensitivities on the order of that can be operated from dc to radio frequencies. Their sensitivity greatly exceeds that of conventional field-effect transistors; however, their temperature range is typically restricted to deep cryogenic temperatures below 4 K. Preliminary work by the supervisory team has demonstrated that single-electron transistors fabricated from chemical vapor deposition grown graphene via feedback-controlled breakdown can operate up to room temperature. The fabrication process for these devices is scalable and arrays of hundreds of graphene single-electron transistors on 1x1 cm2 have already been demonstrated. In this project we will explore how neutron irradiation results in heating and/or charge generation in the device substrate that can be detected by arrays of graphene single-electron transistors. We will also explore potential radiation damage to the graphene devices resulting from prolonged exposure.
The project will use:
* State-of-the-art nanofabrication facilities at Queen Mary, including scanning thermal probe lithography and direct laser write, thin film and atomic layer deposition, and oxygen plasma etching; stretch goals include the use of molecular graphene and porphyrin nanoribbons.
* Fully automated wafer-scale probe stations for fabrication via feedback-controlled breakdown and device characterisation.
* Assembly and packaging, including manual and automated wire bonders.
* Cryogenic transport setups, including a 10 mK dilution refrigerator, a 1.6-300 K cryostat, and an 80-300 K cryogenic probe station.
* AmBe or a Cf source to provide neutrons; stretch goals include the use of sources available in our labs or at other partner universities.
Funding Notes
* Available to Home applicants.
* Applicant required to start in September 2024.
* The studentship arrangement will cover home tuition fees and provide an annual stipend for up to three years starting at £21237.
* The minimum requirement for this studentship opportunity is a good Honours degree (minimum 2(i) honours or equivalent) or MSc/MRes in a relevant discipline.
Application Method:
To apply for this studentship and for entry on to the NTR-Network programme (Full Time) please follow the instructions detailed on the following webpage: Application Link
Deadline for applications: Application considered on a rolling basis.
For informal enquiries about this position, please contact Prof. Jan Mol
Tel: 020 7882 5582
E-mail: j.mol@qmul.ac.uk
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