Dr Carmen Palacios-Berraquero was awarded the Jocelyn Bell Burnell Medal and Prize by the Institute of Physics for her work on 2D materials and quantum optics
The Jocelyn Bell Burnell Medal and Prize has been established since 2007 as the Women in Physics Group award, which is awarded for exceptional early career contributions to physics by a female physicist. Carman Palacios-Berraquero has won the 2018 prize for discovering and patenting a method to create single-photon emitting sites in atomically-thin materials and for using a 2-dimensional decive to all-electrically induce quantum emission from these sites.
Carmen Palacios-Berraquero’s research lies at the interface between two disciplines: 2-dimensional materials and quantum optics. Her PhD thesis title was: 'Quantum-confined Excitons in 2-dimensional Materials'. The family of 2D materials she studies are transition metal dichalcogenides (2D-TMDs), semiconductors offering many technological advantages, such as low power consumption and atomically-precise interfaces.
Carmen's group has developed a method of deterministically creating the single-photon emitting sites in 2D-TMDs in large-scale arrays. These are referred to as quantum dots (QDs), quantum confinement potentials which can trap single-excitons. The excitons recombine radiatively to emit single-photons which is a crucial requirement for many quantum information technology (QIT) applications.
The QDs are formed by placing the flakes over substrates nano-patterned with protrusions which induce local strain and provoke the quantum confinement of excitons at low temperatures. Carmen designed and tested this method after preliminary studies, which included fabricating the samples, performing the optical measurements in several TMDs, and achieving quantum light at different wavelengths. Very few quantum confinement systems can be deterministically engineered in a scalable way.
In another experiment, 2D-QDs were embedded within 2D-heterostructures to form quantum devices. 2D-TMDs and other 2D-materials, such as graphene and hexagonal boron nitride, were used to create quantum light-emitting diodes. Carmen’s optical measurements proved the electrically-driven light was indeed single-photons, and discovered these sites in a new material (WS2) for the first time. Only a few single-photon sources can be triggered electrically and this ability is potentially a great advantage for on-chip quantum technologies.
Carmen is currently working towards using the QDs as a new, optically-addressable matter qubit by capturing single-spins inside them and using field-effect type 2D-devices.
This research represents the marriage of 2D-semiconductor technology with QIT, paving the way for 2D materials as platforms for scalable, on-chip quantum photonics.