Ultrafast terahertz microscopy down to the atomic scale*

Recent developments have allowed terahertz (THz) scanning probe microscopy to achieve unprecedented simultaneous temporal and spatial resolutions. Included in the arsenal of THz microscopy techniques are terahertz scanning tunneling microscopy (THz-STM), which reveals the ultrafast response of a tunnel junction with atomic resolution [1-3], scattering-type scanning near-field optical microscopy (s-SNOM), which reveals the local dielectric function [4-6], and terahertz emission nanoscopy, which reveals local contrast in THz fields generated at the sample surface [7,8]. In this talk I will show examples of the types of experiments that can be done with each technique, including atomically resolved THz-STM snapshot imaging of local electron densities.

[1] T. L. Cocker et al., Nat. Photon., 7, 620 (2013).
[2] T. L. Cocker et al., Nature 539, 263 (2016).
[3] V. Jelic et al., Nat. Phys. 13, 591 (2017).
[4] M. Eisele et al., Nat. Photon. 8, 841 (2014).
[5] M. A. Huber et al., Nat. Nanotechnol. 12, 207 (2017).
[6] F. Mooshammer et al., Nano Lett. 18, 7515 (2018).
[7] P. Klarskov et al., ACS Photon. 4, 2676 (2017).
[8] J. Zhang et al., ACS Photon. 5, 2645 (2018).