ERI: Single Molecule Quantum Magnetometry Sensor

Magnetometer sensors are widely used in a variety of applications, such as robotics, cars, smart phones, and medical equipment. For example, in healthcare, the latest magnetometer sensors enable monitoring and visualizing changes of the magnetic field in the heart or brain, which can be used for accurate diagnosis in a non-invasive manner. To improve sensor performance and further reduce the cost and size to be integrated with circuitry, a new platform of magnetometry is demanded for overcoming the current limitations in modern magnetometer sensors.

A novel device design of an organic chromophore coupled with a mechanical resonator provides an excellent opportunity for the development of ultra-sensitive and highly efficient magnetometer sensors, in which quantum emission from a vibrating single chromophore can effectively reflect the alternation of the environmental magnetic field in all-optical manner. This study will lead to benefits in developing portable, wearable, and high-performance magnetometer sensors working at room temperature.

Successful research will also bring local and underrepresented students strong educational and training opportunities to participate in hands-on research activities in cutting-edge technologies, helping them to become competitive members of the national workforce in the field of quantum information science.

This novel quantum magnetometer sensor is based on an organic chromophore embedded in an organometallic single crystal which is integrated onto a nanomechanical resonator. A single chromophore isolated in the high-purity and the van der Waals bonded organometallic host crystal will offer an advantageous quantum system with reduced spin noise, giving rise to single photon emission with long coherence time.

Through effective coupling with vibrational motions of the mechanical resonator, this molecular quantum emitter is anticipated to detect a variation of external magnetic field with the ultra-high sensitivity and accuracy. Time-correlated interferometric (Hanbury Brown-Twiss, Hong-Ou-Mandel) and photon counting techniques will be employed to advance the fundamental physics of molecular systems and to characterize the sensing performance of this unique molecular quantum magnetometer.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.