Scientists at the University of Tokyo in Japan have for the first time completed the delicate task of arranging quantum sensors at the nanoscale to achieve high-resolution magnetic field imaging

Scientists at the University of Tokyo, Japan, recently used the boron vacancy in the two-dimensional layer of hexagonal boron nitride to complete the fine task of arranging quantum sensors at the nanoscale for the first time, so as to detect very small changes in the magnetic field and achieve high-resolution magnetic field imaging.

Boron nitride is a thin crystalline material containing nitrogen and boron atoms. Artificial spin defects in boron nitride lattice are suitable as sensors.

(a) Boron vacancy defects in hexagonal boron nitride. The vacancy acts as an atom-sized quantum sensor for magnetic field measurements, sensitive to magnetic fields, like a nanoscale "magnetic needle."

(b) photoluminescence of quantum sensor nanoarrays. By analyzing changes in the intensity of photoluminescence in response to microwaves, the researchers were able to measure the magnetic field at each sensor point.

The research team created a thin hexagonal boron nitride film, attached it to the target gold wire, and then bombarded the film with a high-speed helium ion beam, which ejected boron atoms, forming a boron vacancy of 100 square nanometers. Each dot contains many atom-sized vacancies that behave like tiny magnetic needles. The closer the spot is, the better the spatial resolution of the sensor.

As the current flowed through the wire, the researchers measured the magnetic field at each point and found that the measured value of the magnetic field was very close to the simulated value, demonstrating the effectiveness of the high-resolution quantum sensor. Even at room temperature, the researchers were able to detect changes in the spin state of the sensor in the presence of a magnetic field, allowing them to detect local magnetic fields and currents.

In addition, the boron nitride nanofilms only adhere to objects through van der Waals forces, which means that quantum sensors can easily attach to different materials.

High-resolution quantum sensors have potential applications in quantum materials and electronic device research. For example, sensors can help develop hard drives that use nano-magnetic materials as storage elements.

Atom-sized quantum sensors help scientists image the human brain, pinpoint locations, map underground environments, and detect tectonic changes and volcanic eruptions. The nanoscale quantum sensor will also become a "potential stock" for semiconductor, magnetic materials and superconductor applications.

Source: Science and Technology Daily