Symmetry breaking driven by petahertz electron acceleration in a centrosymmetric organic superconductor

Y. Kawakami; T. Amano; H. Ohashi; H. Itoh; Y. Nakamura; H. Kishida; T. Sasaki; G. Kawaguchi; H. M. Yamamoto; K. Yamamoto; S. Ishihara; K. Yonemitsu; S. Iwai

arXiv · 2007.10762

Symmetry breaking driven by petahertz electron acceleration in a centrosymmetric organic superconductor

Y. Kawakami·T. Amano·H. Ohashi·H. Itoh·Y. Nakamura·H. Kishida·T. Sasaki·G. Kawaguchi·H. M. Yamamoto·K. Yamamoto·S. Ishihara·K. Yonemitsu·S. Iwai

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Abstract

Charge acceleration during an intense light field application to solids attracts much attention as elementary processes in high-harmonic generation and photoelectron emission [1-7]. For manipulating such attosecond dynamics of charge, carrier-envelope-phase (CEP:relative phase between carrier oscillation of light field and its envelope function) control has been employed in insulators, nanometal and graphene [8-10]. In superconducting materials, collective control of charge motion is expected because of its strongly coherent nature of quasi-particles. Here, in a layered organic superconductor, second harmonic generation (SHG) is observed by using a single-cycle 6 femtosecond near infrared pulse, which is in contrast to the common belief that even harmonics are forbidden in the centrosymmetric system. The SHG shows a CEP sensitive nature and an enhancement near the superconducting temperature. The result and its quantum many-body analysis indicate that a polarized current is induced by non-dissipative acceleration of charge, which is amplified by superconducting fluctuations. This will lead to petahertz functions of superconductors and of strongly correlated systems.

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Y. Kawakami, T. Amano, H. Ohashi, H. Itoh, Y. Nakamura, H. Kishida, T. Sasaki, G. Kawaguchi, H. M. Yamamoto, K. Yamamoto, S. Ishihara, K. Yonemitsu, S. Iwai. 2020-07-21. Symmetry breaking driven by petahertz electron acceleration in a centrosymmetric organic superconductor. https://arxiv.org/abs/2007.10762

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