Molecular Manipulation Lab

Novel devices created in the MoMaLab

Scanning Quantum Dot Microscopy (SQDM)
An outstanding device created with the help of controlled molecular manipulation is the scanning quantum dot microscope. This microscope is a non-contact AFM to the tip of which a molecular quantum dot is attached. The molecule is placed on the tip by controlled lifting from the surface. Remarkably, the molecule stays in a configuration vertical to the tip surface where its frontier orbitals are electronically decoupled from the metal tip. In this configuration the molecule has the properties of a quantum dot. It can be gated by applying a bias voltage to the surface and charged with a single electron. The principle of scanning quantum dot microscopy is that this gating can also be the result of electrostatic potentials of nanostructures on the surface. Depending on the sign and magnitude of the nanostructure’s electric potential more or less bias voltage is required to change the charge state of the molecular quantum dot. The abrupt change of the charge state can be detected in the non-contact AFM frequency signal. SQDM is a very sensitive method to image electrostatic surface potential with unparalleled lateral resolution and/or speed.

SQDM principle



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News

December 19th, 2020

Postdoc position available

get more information.

October 22nd, 2020

Congratulations to F. Stefan Tautz for being a winner at the Falling Walls and Berlin Science Week in the category Engineering and Technology. Watch the Online live-stream session Breaking the Wall of Building with Molecules

September 2nd, 2020

Introducing machine learning to the nanoscale: "Autonomous robotic nanofabrication with reinforcement learning" Read at Science Advances Press release

July 2020

Our Helmholtz-AI project MomoNano (together with HZB and TU-Berlin) successfully competed for a three year funding by the Helmholtz Association.

October 23th, 2019

We have been granted another 3.5 Mio core‑h on JURECA.

June 27th, 2019

"The theory of scanning quantum dot microscopy" Read at J Phys. Cond. Mat.

June 10th, 2019

New scanning quantum dot microscopy (SQDM) paper online. Quantitative measurements of surface potentials and dipoles. New window to the nanoscale world. Read at Nature Materials Read full-text w/o subscription Press release
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