Periodic Reporting for period 3 - QLIMIT (Challenging The Limits Of Molecular Quantum Interference Effects)
Okres sprawozdawczy: 2023-06-01 do 2024-11-30
Over the last ten years, there has been a growing interest in quantum interference effects observed in molecules. Remarkably, given their fragility in mesoscopic physics, molecular quantum interference effects can be readily observed at room temperature in solution. This robustness comes from the extremely small size of the molecular components (1-2nm) and thereby the small dimensions over which phase coherence is required.
The aim of this project is to challenge the limits of molecular quantum interference effects delivering clear predictions of how to realise these effects in three challenge areas.
WP1 -Beyond single molecules: intermolecular interference effects.
This work package will investigate interference effects between molecules and in monolayers to find systems where intermolecular interference effects emerge with a long-term view to materials.
WP2 - Beyond classical electronics: Quantum gates
Given that interference effects are an indication of phase coherence being maintained across the molecule, we should be able to exploit the quantum nature of the system for more than simply suppressing current. Proposals exist in the literature for realising quantum gates through scattering, so this work package will investigate use the interference effects in molecules to suggest candidate systems for this type of quantum gates.
WP3 - Beyond electron transport: Controlling vibrational energy redistribution
This work package will focus on how to use interference effects to control vibrational energy redistribution within single molecules with an aim of using this to modulate product ratios in organic reactions.
This project takes ideas that have come out of molecular electronics and tests the scope of their application in three neighbouring areas: supramolecular chemistry, quantum computing and organic chemistry. This project takes a first step in these directions, and success in any work package has the possibility to open a whole new field of research.
The aim of this project is to challenge the limits of molecular quantum interference effects delivering clear predictions of how to realise these effects in three challenge areas.
WP1 -Beyond single molecules: intermolecular interference effects.
This work package will investigate interference effects between molecules and in monolayers to find systems where intermolecular interference effects emerge with a long-term view to materials.
WP2 - Beyond classical electronics: Quantum gates
Given that interference effects are an indication of phase coherence being maintained across the molecule, we should be able to exploit the quantum nature of the system for more than simply suppressing current. Proposals exist in the literature for realising quantum gates through scattering, so this work package will investigate use the interference effects in molecules to suggest candidate systems for this type of quantum gates.
WP3 - Beyond electron transport: Controlling vibrational energy redistribution
This work package will focus on how to use interference effects to control vibrational energy redistribution within single molecules with an aim of using this to modulate product ratios in organic reactions.
This project takes ideas that have come out of molecular electronics and tests the scope of their application in three neighbouring areas: supramolecular chemistry, quantum computing and organic chemistry. This project takes a first step in these directions, and success in any work package has the possibility to open a whole new field of research.
The first half of the project has seen us building capacity within all three challenge areas, while battling the uncertainties the pandemic brought. Team members have been hired in all three areas with theoretical work commenced in all work packages and experimental work/collaborations undertaken in two of the three work packages.
Beyond single molecules: intermolecular interference effects.
We have developed procedures to study the effects of intermolecular interactions on charge transport through molecules and monolayers. These have been employed to investigate the impact of intermolecular interactions on molecules where the electron transport is dominated by destructive quantum interference, this project is near completion and is expected to be submitted for publication in 2023.
Together with experimental collaborators, we are investigating rectification observed to be much more significant in monolayers and one would expect from the properties of the single molecules. We have reproduced these trends in our calculations, and are currently working to understand the underlying chemical causes of this behaviour.
Beyond classical electronics: Quantum gates
On the theoretical side, we have conducted initial investigations into how chemical structure controls the phase of the transmitted wave function, but have not been able to establish clear chemical trends at this time. We have identified single molecule inductance experiments as a promising technique to provide experimental feedback for the key questions in this work package. We have started work to establish single-molecule inductance measurement capabilities and expect to conduct an initial experiments in 2023.
Beyond electron transport: Controlling vibrational energy redistribution
This work package has required the most extensive code development work in the project, and we have developed code to calculate heat transport through single molecules bound in conducting junctions, as well as code to model vibrational energy redistribution in molecules. These two methods are now being employed employed to explore relevant applications. In the case of heat transport, we are investigating candidate systems for molecular thermal insulators and thermoelectric materials. Our code to describe intramolecular vibrational energy redistribution is currently being compared with results from molecular dynamics calculations, and in 2023 will be tested against experiments.
We have a number of draft manuscripts in preparation from work packages 1 and 3 and expect these to be submitted in 2023. Initial results from all three work packages have been presented by team members at a number of international conferences.
Beyond single molecules: intermolecular interference effects.
We have developed procedures to study the effects of intermolecular interactions on charge transport through molecules and monolayers. These have been employed to investigate the impact of intermolecular interactions on molecules where the electron transport is dominated by destructive quantum interference, this project is near completion and is expected to be submitted for publication in 2023.
Together with experimental collaborators, we are investigating rectification observed to be much more significant in monolayers and one would expect from the properties of the single molecules. We have reproduced these trends in our calculations, and are currently working to understand the underlying chemical causes of this behaviour.
Beyond classical electronics: Quantum gates
On the theoretical side, we have conducted initial investigations into how chemical structure controls the phase of the transmitted wave function, but have not been able to establish clear chemical trends at this time. We have identified single molecule inductance experiments as a promising technique to provide experimental feedback for the key questions in this work package. We have started work to establish single-molecule inductance measurement capabilities and expect to conduct an initial experiments in 2023.
Beyond electron transport: Controlling vibrational energy redistribution
This work package has required the most extensive code development work in the project, and we have developed code to calculate heat transport through single molecules bound in conducting junctions, as well as code to model vibrational energy redistribution in molecules. These two methods are now being employed employed to explore relevant applications. In the case of heat transport, we are investigating candidate systems for molecular thermal insulators and thermoelectric materials. Our code to describe intramolecular vibrational energy redistribution is currently being compared with results from molecular dynamics calculations, and in 2023 will be tested against experiments.
We have a number of draft manuscripts in preparation from work packages 1 and 3 and expect these to be submitted in 2023. Initial results from all three work packages have been presented by team members at a number of international conferences.
In all work packages, we have moved beyond the state of the art, and this is expected to continue and accelerate in the second half of the project. The theoretical methods developed as part of this project are largely in line with prior work in the area, and we expect to see our results move significantly beyond the state of the art as we increasingly focus on applications.