| Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2014: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2013: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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| Outline of Final Research Achievements |
We realized nonadiabatic excitation to an s-wave superconductor NbTiN by using an intense monocycle THz pulse, and reported time-resolved observation of the Higgs mode as a free oscillation of the order parameter amplitude after the nonadiabatic perturbation. This collective mode is a condensed matter analog of the Higgs bosons in particle physics. We also examined the dynamics of the order parameter during the irradiation of the strong THz electric field, and showed that strong sub-gap electric field induces forced oscillation of the order parameter with twice the pump frequency, accompanied by third harmonics generation (THG). We found that the forced oscillation and THG are strongly enhanced when the nonlinear driving frequency is equal to the Higgs mode frequency. This result is the first discovery of the resonance between light and Higgs mode in nonlinear response regime and paves a way for ultrafast control of macroscopic quantum condensates by light.
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