Quantum regime of nanogaps studied with terahertz fields
| Date/Time: | Thursday, 09 Feb 2017 from 4:10 pm to 5:00 pm |
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| Location: | Physics 3 |
| Phone: | 515-294-7377 |
| Channel: | College of Liberal Arts and Sciences |
| Actions: | Download iCal/vCal | Email Reminder |
Quantum tunneling in nanogap metal structures presents an interesting aspect of incorporating quantum mechanics into classical optics. Terahertz quantum plasmonics is demonstrated in metal separations well over 1 nm by exposing the nanogaps to high-power terahertz pulses. A giant nonlinear optical response in the form of 50% decrease of the normalized terahertz transmittance is observed as transient terahertz electric fields are enhanced up to 5 V/nm inside the nanogaps. Also, terahertz time-domain spectroscopy is used to identify the sub-picosecond time evolution of both the phase and amplitude of the induced ac tunneling current and applied field in subnanometer gaps. The dc component of the tunneling current measured with I-V probes implies that peak currents reach up to the Ampere level. We expect that the research introduced here will merge the knowledge of conventional dc electronic transport measurements, quantum plasmonics, and the study of ultrafast physics and nonlinear terahertz spectroscopy.