4-Tip Scanning Tunneling Microscope for Ultrahigh Vacuum Operation at 100 mK

• Subject Area: Condensed Matter Physics
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 458555100

The project combines key expertise of the II. Institute of Physics at RWTH Aachen University and the Peter-Grünberg Institute 3 (PGI-3) at Forschungszentrum Jülich to set up a worldwide unique instrument supporting, in particular, the aims of the excellence cluster ML4Q. It will be the first four-tip scanning tunneling microscope that operates at temperatures below 1 K. We aim to work at temperatures down to 0.1 K within ultrahigh vacuum additionally providing a 3D magnetic vector field and high frequency voltages up to 30 GHz at each tip. This addresses the detection and spectroscopy as well as first quantum transport experiments of Majorana zero modes within nanostructures that are prepared in-situ with the ultimate aim to achieve robustly operating Majorana qubits. The assembly of such qubits is one central promise of the excellence cluster ML4Q. As such, the instrument will crucially contribute to the success of the cluster. The novel instrument will, moreover, offer multiple options of other types of experiments as described in the “Supplements of Research”.While the II. Institute of Physics contributes its long-term expertise of scanning tunneling microscopy at sub-1K temperatures and high frequency to the project, PGI-3 is a worldwide leading group concerning the set-up of four-tip scanning tunneling microscopes.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Vier-Spitzen Rastertunnelmikroskop für 100 mK im Ultrahochvakuum
• Instrumentation Group: 5091 Rasterkraft-Mikroskope
• Applicant Institution: Rheinisch-Westfälische Technische Hochschule Aachen
• Leader: Professor Dr. Markus Morgenstern