Microwave detection using Rydberg excitons in cuprous oxide
Lead Research Organisation:
Durham University
Department Name: Physics
Abstract
Technical Work to be Undertaken
The objective of the CASE studentship with DSTL is to start a new direction based on the use of the excitonic state for sensitive microwave detection. We hope to demonstrate the excitons - bounds states of electrons and holes - can be simultaneously strongly coupled to microwave and optical radiation, enabling microwave to optical conversion and detection.
It builds on a 4 year EPSRC grant that started on 01/05/2017 (Solid State Superatoms), which is collaboration with Cardiff University (PI Dr Stephen Lynch), and which will provide the underpinning equipment. The CASE award is independent of the existing collaboration with Cardiff University, but there is some cross-over between the two projects.
Current Level of Maturity of the Work
The Durham/Cardiff collaboration has existed since 2015; we have preliminary results (observation of Rydberg excitons up to principal quantum number n=12), and developed methods for sample preparation and spectroscopy. The microwave sensing direction is underpinned to some extent by our positive experience with atomic Rydberg states, but is highly innovative and carries some degree of risk.
Expected Deliverables
As part of a CASE award, DSTL would host the student for a 3 month placement, providing access to knowledge and the potential for recruitment. Additional benefits include continuing access to expertise and advice on potential technologies. Reports can be delivered if required.
The objective of the CASE studentship with DSTL is to start a new direction based on the use of the excitonic state for sensitive microwave detection. We hope to demonstrate the excitons - bounds states of electrons and holes - can be simultaneously strongly coupled to microwave and optical radiation, enabling microwave to optical conversion and detection.
It builds on a 4 year EPSRC grant that started on 01/05/2017 (Solid State Superatoms), which is collaboration with Cardiff University (PI Dr Stephen Lynch), and which will provide the underpinning equipment. The CASE award is independent of the existing collaboration with Cardiff University, but there is some cross-over between the two projects.
Current Level of Maturity of the Work
The Durham/Cardiff collaboration has existed since 2015; we have preliminary results (observation of Rydberg excitons up to principal quantum number n=12), and developed methods for sample preparation and spectroscopy. The microwave sensing direction is underpinned to some extent by our positive experience with atomic Rydberg states, but is highly innovative and carries some degree of risk.
Expected Deliverables
As part of a CASE award, DSTL would host the student for a 3 month placement, providing access to knowledge and the potential for recruitment. Additional benefits include continuing access to expertise and advice on potential technologies. Reports can be delivered if required.
Organisations
Publications
Gallagher L
(2022)
Microwave-optical coupling via Rydberg excitons in cuprous oxide
in Physical Review Research
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509462/1 | 01/10/2016 | 30/09/2021 | |||
| 1929797 | Studentship | EP/N509462/1 | 01/10/2017 | 30/09/2021 | Liam Gallagher |
| Description | Microwave detection using Rydberg excitons in cuprous oxide has been achieved. Excitons are atomic like quasi-particles which exist within semiconductors. In cuprous oxide, highly excited exciton states have been observed. These highly excited states are termed Rydberg excitons- as they are analogous to Rydberg atoms. The aim of this project demonstrate that Rydberg excitons can couple to microwave fields. The coupling of Rydberg states to microwave fields is well studied for atomic Rydberg states but has not been demonstrated in a solid-state Rydberg system. We have successfully demonstrated that the microwave field can be coupled to the Rydberg excitons. The coupling occurs due to the microwave field driving electric-dipole transitions between Rydberg states of opposite parity. We have explored the microwave coupling using two different optical excitation schemes. We have shown that the microwave field can coherently modulate the optical input, which is the first step in producing a microwave to optical converter using Rydberg excitons. |
| Exploitation Route | Microwave to optical conversion is a useful tool in classical telecommunications as well as for quantum computation. In quantum computing superconducting qubits operating at microwave frequencies have shown a lot of promise, but readout of the signal is a challenge. This system could be used a new readout mechanism for superconducting qubits. As it is already at cryogenic temperatures (4K) integration with superconducting qubits would be possible. Additionally, cuprous oxide could be used to characterize the near-field structure of cryogenic microwave devices, which could lead to improvements in the design of these devices. |
| Sectors | Other |
| URL | https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.4.013031 |
| Title | Microwave-optical coupling via Rydberg excitons in cuprous oxide [dataset] |
| Description | We report exciton-mediated coupling between microwave and optical fields in cuprous oxide (Cu2O) at low temperatures. Rydberg excitonic states with principal quantum number up to n= 12 were observed at 4 K using both one-photon (absorption) and two-photon (second harmonic generation) spectroscopy. Near resonance with an excitonic state, the addition of a microwave field significantly changed the absorption lineshape, and added sidebands at the microwave frequency to the coherent second harmonic. Both effects showed a complex dependence on n and angular momentum, l. All of these features are in semi-quantitative agreement with a model based on intra-band electric dipole transitions between Rydberg exciton states. With a simple microwave antenna we already reach a regime where the microwave coupling (Rabi frequency) is comparable to the nonradiatively broadened linewidth of the Rydberg excitons. The results provide a new way to manipulate excitonic states, and open up the possibility of a cryogenic microwave to optical transducer based on Rydberg excitons. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2022 |
| Provided To Others? | Yes |
| Impact | This is the dataset supporting the demonstrated microwave-exciton coupling in curpous oxide. These result demonstrate the first coherent coupling of Rydberg excitons and microwave fields. |
| URL | http://collections.durham.ac.uk/files/r13x816m66s |