Dynamic interference of the high harmonics from photoisomerizing 1,3-cyclohexadiene

Abstract

The ionization potential difference between photoexcited and ground-state molecules results in a phase difference between their high harmonics, which causes high harmonic interference. The interference enables us to reveal how ionization potential of the photoexcited molecules evolves along the electronic relaxation path from the Franck–Condon state to the electronic ground state. We observe the ultrafast electron dynamics of a photoisomerizing molecule, 1,3-cyclohexadiene, via high harmonic interference. The experimental observations reveal that the electronic relaxation of 1,3-cyclohexadiene takes 200 fs, and the photoisomerization to 1, 3, 5-hexatriene takes an additional 450 fs.

Real-time observation of the Woodward–Hoffmann rule for 1,3-cyclohexadiene by femtosecond soft X-ray transient absorption

“…The recent development of ultrafast laser technology has enabled the observation of reaction dynamics on a timescale of femtoseconds to attoseconds. The reaction dynamics of CHD has been investigated using various spectroscopic techniques [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and theoretical approaches. [26][27][28][29][30][31][32] Followed by the excitation to the S 1 (1B) state, the configurational coordinate diagram shown in the right panel of Fig.…”