Quantum Sensing Laboratory
We are pushing the limits of measurement sensitivity.
Our
new laboratory focuses on utilizing quantum defects in diamond - specifically
Nitrogen-Vacancy (NV) centers - to detect magnetic fields with atomic-scale
resolution. By combining quantum physics with nanotechnology, we aim to build
sensors capable of performing NMR spectroscopy on the
nanoscale.
The Quantum Sensor
The core of our research is the Nitrogen-Vacancy (NV) center in diamond. This atomic defect acts as a single spin system that can be manipulated using microwave pulses and read out using laser light.
Because the NV center is protected by the diamond lattice, it retains its quantum properties even at room temperature. This allows us to use it as an ultra-sensitive magnetometer, capable of sensing the faint magnetic signals from atoms in its vicinity.
- Room Temperature Operation: No need for cryogenics.
- Optical Readout: We use lasers to read-out the sensor quantum state.
- Nanoscale Resolution: Sensing happens at the atomic scale.
Schematic of the experiment: Green laser light initializes the sensor, and red fluorescence reveals the magnetic environment.
Nanostructuring & Fabrication
To get the sensor close enough to the sample, we cannot use standard bulk diamonds. We need to sculpt the diamond into functional nanostructures – such as nanopillars or diamond gratings – that guide light efficiently and allow for precise positioning.
Collaboration with FZU We work in close collaboration with the group of Prof. Alexander Kromka at the Institute of Physics (FZU). Their team provides expertise in:
- CVD Diamond Growth: Growing high-purity single crystals.
- Nanofabrication: Etching diamond into photonic structures.
- Surface Termination: Controlling the surface chemistry to protect the quantum spins.
The Experiment
Our goal is to build a compact, integrated platform for Nano-NMR. Conventional NMR (Nuclear Magnetic Resonance) requires massive superconducting magnets and large sample volumes. By using NV centers, we are developing a system that can detect the chemical composition of thin films or even single molecules.
Our setup integrates:- Widefield Microscopy: For optical addressing of NV center ensembles.
- Microwave & RF Control: To manipulate the quantum spin states of the sensor and the target nuclei.
- Permanent Magnets: To provide the necessary bias fields without bulky equipment.
