scholarly journals Localization length scales of triplet excitons in singlet fission materials

2015 ◽  
Vol 92 (11) ◽  
Author(s):  
Sam L. Bayliss ◽  
Karl J. Thorley ◽  
John E. Anthony ◽  
Hélène Bouchiat ◽  
Neil C. Greenham ◽  
...  
2017 ◽  
Vol 145 (11) ◽  
pp. 4575-4592 ◽  
Author(s):  
Craig H. Bishop ◽  
Jeffrey S. Whitaker ◽  
Lili Lei

To ameliorate suboptimality in ensemble data assimilation, methods have been introduced that involve expanding the ensemble size. Such expansions can incorporate model space covariance localization and/or estimates of climatological or model error covariances. Model space covariance localization in the vertical overcomes problematic aspects of ensemble-based satellite data assimilation. In the case of the ensemble transform Kalman filter (ETKF), the expanded ensemble size associated with vertical covariance localization would also enable the simultaneous update of entire vertical columns of model variables from hyperspectral and multispectral satellite sounders. However, if the original formulation of the ETKF were applied to an expanded ensemble, it would produce an analysis ensemble that was the same size as the expanded forecast ensemble. This article describes a variation on the ETKF called the gain ETKF (GETKF) that takes advantage of covariances from the expanded ensemble, while producing an analysis ensemble that has the required size of the unexpanded forecast ensemble. The approach also yields an inflation factor that depends on the localization length scale that causes the GETKF to perform differently to an ensemble square root filter (EnSRF) using the same expanded ensemble. Experimentation described herein shows that the GETKF outperforms a range of alternative ETKF-based solutions to the aforementioned problems. In cycling data assimilation experiments with a newly developed storm-track version of the Lorenz-96 model, the GETKF analysis root-mean-square error (RMSE) matches the EnSRF RMSE at shorter than optimal localization length scales but is superior in that it yields smaller RMSEs for longer localization length scales.


2020 ◽  
Vol 11 (4) ◽  
pp. 1261-1267 ◽  
Author(s):  
Jian Han ◽  
Qing Xie ◽  
Jun Luo ◽  
Gang-Hua Deng ◽  
Yuqin Qian ◽  
...  

2019 ◽  
Vol 141 (32) ◽  
pp. 12907-12915 ◽  
Author(s):  
Jesse R. Allardice ◽  
Arya Thampi ◽  
Simon Dowland ◽  
James Xiao ◽  
Victor Gray ◽  
...  

2014 ◽  
Vol 112 (23) ◽  
Author(s):  
Sam L. Bayliss ◽  
Alexei D. Chepelianskii ◽  
Alessandro Sepe ◽  
Brian J. Walker ◽  
Bruno Ehrler ◽  
...  

ChemPhysChem ◽  
2011 ◽  
Vol 12 (16) ◽  
pp. 2891-2894 ◽  
Author(s):  
Chen Wang ◽  
Diana E. Schlamadinger ◽  
Varsha Desai ◽  
Michael J. Tauber

2019 ◽  
Vol 141 (44) ◽  
pp. 17949-17949
Author(s):  
Jesse R. Allardice ◽  
Arya Thampi ◽  
Simon Dowland ◽  
James Xiao ◽  
Victor Gray ◽  
...  

2020 ◽  
Vol 12 (4) ◽  
pp. 391-398 ◽  
Author(s):  
Nadezhda V. Korovina ◽  
Christopher H. Chang ◽  
Justin C. Johnson

2019 ◽  
Vol 70 (1) ◽  
pp. 323-351 ◽  
Author(s):  
Andrew J. Musser ◽  
Jenny Clark

Entanglement of states is one of the most surprising and counterintuitive consequences of quantum mechanics, with potent applications in cryptography and computing. In organic semiconductor materials, one particularly significant manifestation is the spin-entangled triplet-pair state, which consists of a pair of localized triplet excitons coupled into an overall spin-0, -1, or -2 configuration. The most widely analyzed of these is the spin-0 pair, denoted1(TT), which was initially invoked in the 1960s to explain delayed fluorescence in acene films. It is considered an essential gateway state for triplet-triplet annihilation and the reverse process, singlet fission, enabling interconversion between one singlet and two triplet excitons without any change in overall spin. This state has returned to the forefront of organic materials research in recent years, thanks both to its central role in the resurgent field of singlet fission and to its implication in a host of exotic new photophysical behaviors. Here we review the properties of triplet-pair states, from first principles to recent experimental results.


2018 ◽  
Vol 9 (23) ◽  
pp. 6731-6738 ◽  
Author(s):  
Yan Wan ◽  
Gary P. Wiederrecht ◽  
Richard D. Schaller ◽  
Justin C. Johnson ◽  
Libai Huang

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