Quantum Sensing

Quantum Sensing

Measurements of magnetic properties on the atomic scale require a sensor with the intrinsic sensitivity for single spin detection, a size comparable to systems under investigation, and the capability for measurements without strongly influencing the spin properties of the studied systems. A prime example for such a quantum sensor is the nitrogen-vacancy (NV) center in diamond.

Using atomic force microscopy (AFM) techniques to position the sensor for magnetic resonance imaging measurements with subatomic precision with respect to the atoms or molecules of interest, highest spatial imaging resolution can be achieved. In combination with the inherent high energy resolution of Electron Spin Resonance and Nuclear Magnetic Resonance spectroscopy and imaging, fundamental properties and spin interactions of atoms and molecules can be investigated on the sub-Å and sub-neV scale.

NV magnetometry is applied to image single (bio)molecules at ultimate spatial resolution and to develop scalable quantum technologies for quantum information processing. Work done in collaboration with the Fellow Group of Prof. Wrachtrup .

Another path to electron spin resonance spectroscopy (ESR) on single atoms and molecules is pursued within the ERC Consolidator Grant by Dr. Christian Ast. Here, ESR is combined with low-temperature scanning tunneling microscopy to investigate individual atomic and molecular spin systems. The spin degeneracy is lifted by an external magnetic field and then excited by a microwave. The measurement of the excited spin state is realized through a spin-polarized tip. The goal is to employ pulsed ESR to better understand the spin dynamics of interacting spin systems.

Responsible Scientists

Dr. Aparajita Singha
Dr. Christian Ast

Team Members

Domenico Paone, Dinesh Pinto, Piotr Kot, Maximilian Uhl, Jeffrey Neethi Neethirajan, Janis Siebrecht, Dr. Robert Drost

Key Publications

D. Paone, D. Pinto, G. Kim, L. Feng, M-J. Kim, R. Stöhr, A. Singha, S. Kaiser, G.Logvenov, B. Keimer, J. Wrachtrup, and K. Kern
All-Optical and Microwave-Free Detection of Meissner Screening using Nitrogen-Vacancy Centers in Diamond
J. of Appl. Phys. 129, 024306 (2021) DOI: 10.1063/5.0037414

Dinesh Pinto, Domenico Paone, Bastian Kern, Tim Dierker, René Wieczorek, Aparajita Singha, Durga Dasari, Amit Finkler, Wolfgang Harneit, Jörg Wrachtrup, and Klaus Kern
Readout and control of an endofullerene electronic spin
Nature Commun. 11, 6405 (2020)

Piotr Kot, Robert Drost, Maximilian Uhl, Joachim Ankerhold, Juan Carlos Cuevas and Christian R. Ast
Microwave-assisted tunneling and interference effects in superconducting junctions under fast driving signals
Phys. Rev. B 101, 134507 (2020)

Lukas Schlipf, Thomas Oeckinghaus, Kebiao Xu, Durga Bhaktaatsala Rao Dasari, Andrea Zappe, Felipe Fávaro de Oliveira, Bastian Kern, Mykhailo Azarkh, Malte Drescher, Markus Ternes, Klaus Kern, Jörg Wrachtup, and Amit Finkler
Molecular quantum spin network controlled by a single qubit
Science Advances 3, e1701116 (2017)

Eike Schäfer-Nolte, Lukas Schlipf, Markus Ternes, Friedemann Reinhard, Klaus Kern, and Jörg Wrachtrup 
Tracking Temperature Dependent Relaxation Times of Individual Ferritin Nanomagnets with a Wide-band Quantum Spectrometer 
Phys. Rev. Lett. 113, 217204 (2014) 

E. Schaefer-Nolte, F. Reinhard, M. Ternes, J. Wrachtrup, and K. Kern 
A diamond-based scanning probe spin sensor operating at low temperature 
in ultra-high vacuum 
Rev. Sci. Instrum. 85, 013701 (2014) 

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