Home > Press > Lattice distortion of perovskite quantum dots induces coherent quantum beating
![]() |
Lattice distortion in lead halide perovskite quantum dots leads to a fine structure gap and coherent exciton quantum beating CREDIT DICP |
Abstract:
A research group led by Prof. WU Kaifeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Dr. Peter C. Sercel from the Center for Hybrid Organic Inorganic Semiconductors for Energy, recently reported the utilization of lattice distortion in lead halide perovskite quantum dots (QDs) to control their exciton fine structure.
The study was published in Nature Materials on Sept. 8.
It is well known that shape or crystal anisotropy in QDs, which are tiny semiconductor nanoparticles, results in energy splitting of their optically bright excitons (bound electron-hole pairs), known as fine structure splitting (FSS). These excitons form an important playground for quantum information science. For example, the excitons' FSS can be exploited for coherent control of quantum states for quantum computing, or for polarization-entangled photon-pairs in quantum optics, although for the latter it is important to suppress the magnitude of splitting.
Traditionally, studying FSS usually requires single or just a few QDs at liquid-helium temperature, because of its sensitivity to QD size and shape. Measuring FSS at an ensemble-level, let alone controlling it, seems impossible unless all the dots are made to be nearly identical.
In this study, by using ensemble-level femtosecond polarized transient absorption, the researchers observed clear bright-exciton FSS in solution-processed CsPbI3 perovskite QDs, which is manifested as exciton quantum beats (periodic oscillations of kinetic traces).
“Even more amazingly, the beat frequency, as determined by the FSS energy, of a given sample can be continuously controlled by changing the temperature. This is an unprecedented result, meaning that now scientists can facilely control FSS through temperature,” said Prof. WU.
The researchers also found that the temperature-dependent FSS was related to the interesting, highly-dynamic lattice of lead halide perovskites. Lowering the temperature led to a more distorted lead-iodide octahedral framework.
Calculations indicated that, because these orthorhombic-phase QDs were actually still bounded by the pseudocubic family of crystal planes, the lattice distortion results in an avoided crossing fine-structure gap between bright exciton. This gap was responsible for the observed FSS, and it could be detected in spite of QD size and shape heterogeneity across an ensemble sample.
"Lattice distortion in CsPbI3 perovskites is well known in the photovoltaic community, as it is connected to the issue of phase stability of perovskite solar cells, but nobody has previously connected it experimentally to the exciton fine structure" said Prof. WU. "Our study demonstrates that this material property can actually be harnessed to control the bright-exciton splitting in quantum dots for quantum information technologies."
####
For more information, please click here
Contacts:
Jean Wang
Dalian Institute of Chemical Physics, Chinese Academy Sciences
Office: 41182464221
Copyright © Dalian Institute of Chemical Physics, Chinese Academy Sciences
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related Links |
Related News Press |
Quantum Physics
Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025
News and information
Flexible electronics integrated with paper-thin structure for use in space January 17th, 2025
Perovskites
KAIST researchers introduce new and improved, next-generation perovskite solar cell November 8th, 2024
Efficient and stable hybrid perovskite-organic light-emitting diodes with external quantum efficiency exceeding 40 per cent July 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Possible Futures
Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025
The National Space Society Congratulates SpaceX on Starship’s 7th Test Flight: Latest Test of the Megarocket Hoped to Demonstrate a Number of New Technologies and Systems January 17th, 2025
Chip Technology
Enhancing transverse thermoelectric conversion performance in magnetic materials with tilted structural design: A new approach to developing practical thermoelectric technologies December 13th, 2024
Bringing the power of tabletop precision lasers for quantum science to the chip scale December 13th, 2024
Nanofibrous metal oxide semiconductor for sensory face November 8th, 2024
Discoveries
Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025
Announcements
Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025
The National Space Society Congratulates SpaceX on Starship’s 7th Test Flight: Latest Test of the Megarocket Hoped to Demonstrate a Number of New Technologies and Systems January 17th, 2025
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Flexible electronics integrated with paper-thin structure for use in space January 17th, 2025
Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025
Quantum Dots/Rods
A new kind of magnetism November 17th, 2023
IOP Publishing celebrates World Quantum Day with the announcement of a special quantum collection and the winners of two prestigious quantum awards April 14th, 2023
Qubits on strong stimulants: Researchers find ways to improve the storage time of quantum information in a spin rich material January 27th, 2023
NIST’s grid of quantum islands could reveal secrets for powerful technologies November 18th, 2022
Quantum nanoscience
Researchers succeed in controlling quantum states in a new energy range December 13th, 2024
Quantum researchers cause controlled ‘wobble’ in the nucleus of a single atom September 13th, 2024
![]() |
||
![]() |
||
The latest news from around the world, FREE | ||
![]() |
![]() |
||
Premium Products | ||
![]() |
||
Only the news you want to read!
Learn More |
||
![]() |
||
Full-service, expert consulting
Learn More |
||
![]() |