2020 Fiscal Year Research-status Report
Theoretical study of nonlinear optical responses of ultracold atomic systems: towards a high-resolution coherent multidimensional spectroscopy investigation of quantum many-body effects
Project/Area Number |
19K14638
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Research Institution | Kyoto University |
Principal Investigator |
Nguyen Thanh 京都大学, 工学研究科, 講師 (50736337)
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | many-body interaction / Mott transition / coherent spectroscopy / nonlinear response / molecular polariton / reaction rate / superreaction / collective enhancement |
Outline of Annual Research Achievements |
Interactions between particles in quantum many-body systems play a crucial role in determining the electric, magnetic, optical, and thermal properties of the system. The recent progress in the laser-pulse technique has enabled the manipulations and measurements of physical properties on ultrafast timescales. We proposed a method for the direct and ultrafast probing of quantum many-body interaction through coherent two-dimensional (2D) spectroscopy [1]. Up to a moderate interaction strength, the inter-particle interaction manifests itself in the expansion of the signal away from the diagonal axis in the 2D spectrum before the signal shrinks to a single diagonal peak as the system approaches the Mott-insulating phase in the strongly interacting regime. The evolution of the 2D spectrum as a function of the time delay between the second and third laser pulses can provide important information on the ultrafast time variation of the interaction. We also investigated the effect of molecular vibration polariton, a hybrid state of light and matter formed by strongly coupling a molecular vibration mode to an infrared cavity, on the rate of an electron transfer reaction [2]. We proposed a novel superreaction with the collective enhancement of reaction rate by molecular exciton polariton [3]. [1] N. T. Phuc, P. Q. Trung, arXiv:2009.08598 (2020). [2] N. T. Phuc, P. Q. Trung, A. Ishizaki, Sci. Rep. 10, 7318 (2020). [3] N. T. Phuc, arXiv:2103.16166 (2021).
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Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
Following the research plan, we have studied coherent two-dimensional (2D) spectroscopy of a quantum many-body system of particles moving in a lattice. We proposed a method for the direct and ultrafast probing of quantum many-body interaction through 2D spectroscopy [1]. We showed that the 2D spectroscopy can be used to study the Mott transition and the nonequilibrium dynamics of the system across the transition. The progress of the study of coherent 2D spectroscopy is slightly slower than the original plan as we have been studying the related topic of molecular polaritons at the same time. We investigated the effect of molecular vibration polariton, a hybrid state of light and matter formed by strongly coupling a molecular vibration mode to an infrared cavity, on the rate of an electron transfer reaction [2]. We also proposed a novel superreaction with the collective enhancement of reaction rate by molecular exciton polariton [3]. In addition, after moving to Kyoto University, I had to start giving several lectures to both undergraduate and graduate students. These teaching works took me a lot of time. [1] N. T. Phuc, P. Q. Trung, arXiv:2009.08598 (2020). [2] N. T. Phuc, P. Q. Trung, A. Ishizaki, Sci. Rep. 10, 7318 (2020). [3] N. T. Phuc, arXiv:2103.16166 (2021).
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Strategy for Future Research Activity |
In the fiscal year 2022, I plan to study coherent two-dimensional (2D) spectroscopy of a superconductor to investigate if 2D spectroscopy can be used to probe the Cooper pairing. If I have time, I will also study 2D spectroscopy of other systems.
I will continue to explore molecular polaritons to seek for new phenomena and applications of this hybrid state of light and matter.
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Causes of Carryover |
There is a small amount of money left in this fiscal year. It will be used in the next fiscal year for the continuing research.
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Research Products
(6 results)