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Finite Temperature Dynamical Density Matrix Renormalization Group for Spectroscopy in Frequency Domain.
Tong Jiang1, Weitang Li1, Jiajun Ren1
1MOE Key Laboratory of Organic OptoElectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China.
We introduce a new method combining dynamical density matrix renormalization group (DDMRG) with matrix product states (MPS) for calculating molecular aggregate spectroscopy. This approach offers accurate, efficient, and parallelizable simulations at finite temperatures.
Area of Science:
- Quantum chemistry
- Condensed matter physics
- Spectroscopy
Background:
- Calculating finite-temperature spectroscopy for molecular aggregates is computationally challenging.
- Existing methods may suffer from error accumulation during time evolution.
Purpose of the Study:
- To develop a novel, accurate, and efficient computational method for finite-temperature spectroscopy of molecular aggregates.
- To leverage the matrix product state (MPS) formulation of the dynamical density matrix renormalization group (DDMRG).
Main Methods:
- Casting the dynamical density matrix renormalization group (DDMRG) into the matrix product state (MPS) formulation.
- Utilizing a frequency domain algorithm to avoid time evolution errors.
- Implementing graphic processing unit (GPU) acceleration for enhanced performance.
Main Results:
- Accurate simulation of optical spectra for vibronic model systems, including a dimer and a perylene bisimide (PBI) J-aggregate.
- Demonstrated avoidance of time evolution error accumulation.
- Significant performance boost through GPU acceleration.
Conclusions:
- The DDMRG-MPS method provides a highly accurate and efficient approach for finite-temperature spectroscopy of molecular aggregates.
- The method is suitable for parallelization and GPU acceleration, enabling the study of complex systems.
- The study discusses the relationship between emission strength and exciton thermal coherent length in aggregates.
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