Researchers tap fluorescence changes in special, diamond sensors to image time-varying fields.

Researchers from the Indian Institutes of Technology (IIT) at Mumbai and Kharagpur have built a microscope that can image magnetic fields within microscopic two-dimensional samples that change over milliseconds.

This has a huge potential for scientific applications, such as in measuring the biological activity of neurons and the dynamics of vortices in superconductors.

The work, led by IIT Bombay professor Kasturi Saha, from the Department of Electrical Engineering, has been published in  Scientific Reports. 

This is the first time that such a tool has been built to image magnetic fields that change within milliseconds. 

The team had started a collaboration with IIT Kharagpur in 2017 with the ambitious target of building a novel system to image the brain. They collaborated with Sharba Bandopadhyay, who brought in an expertise in neurobiology and bioengineering to complement the knowledge of quantum optics, quantum computing and quantum sensing that was Prof. Saha’s forte.

“We have, along with PhD student Madhur Parashar, developed an algorithm to image neurons in 3D using NV quantum sensors,” says Prof. Saha.

This work was published in  Communications Physics in 2020. We have jointly filed a patent for the present work, she adds.

• Researchers from the Indian Institutes of Technology (IIT) at Mumbai and Kharagpur have built a microscope that can image magnetic fields within microscopic two-dimensional samples that change over milliseconds.
• Prof. Saha explains that the ideal frame rate to capture a changing magnetic field is one that captures data at twice the frequency of the changing field.
• The key aspect of this sensor is a “nitrogen-vacancy (NV) defect centre” in a diamond crystal. Such NV centres act as pseudo atoms with electronic states that are sensitive to the fields and gradients around them (magnetic fields, temperature, electric field and strain).

source/content: thehindu.com(headline edited)