Team Members: Yona Ben-Reuven

Supervisors / Mentors: Nir Bar-Gil, Amir Abramovich

 

This project focuses on enhancing the coherence time of nitrogen-vacancy (NV) centers in diamonds, a critical factor for applications in quantum sensing and quantum information. NV centers are created by replacing two adjacent carbon atoms in the diamond lattice with one nitrogen atom, leading to a defect with unique spin properties. These spin states can be manipulated and measured, but their coherence time (T₂) — the duration over which the quantum state remains stable — is limited, particularly in dense NV ensembles due to increased spin-spin interactions.

The project aims to overcome this limitation by using Hamiltonian engineering and dynamical decoupling techniques. Specifically, it employs pulse sequences with icosahedral symmetry to suppress unwanted interactions and extend T₂. The approach involves designing pulse sequences to achieve a target Hamiltonian that weakens decoherence-inducing interactions. Experimental results show a significant improvement, with coherence time increasing from approximately 1 µs to 212 µs.

By boosting coherence time, the sensitivity of NV-based quantum sensors is significantly enhanced. This work represents a step forward in making NV centers more practical for high-resolution magnetic field sensing and other quantum technologies.