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Researchers at the Raman Research Institute (RRI) have developed a new technology to measure the invisible forces of magnetism—from inside the human brain to the depths of outer space—without requiring bulky shielding.

What is a Magnetometer?

A magnetometer is a special device that measures changes in magnetic fields. For example, geologists use magnetometers to find minerals underground because different rocks have different magnetic properties. Doctors also use them in advanced medical imaging to see what's happening inside the human body.

How Do High-Tech Magnetometers Work?

Many powerful magnetometers, known as "Optically Pumped Atomic Magnetometers (OPAMs)" or "Spin Exchange Relaxation Free (SERF) magnetometers," work by observing how light interacts with small atoms.

When the light passes through, a weak magnetic field makes the light "twist" or change its direction of vibration. Scientists call this "polarization rotation."

By precisely measuring how much the light twists, the magnetometers can figure out the strength of the magnetic field.  

While current high-tech magnetometers are very sensitive, they face a few big challenges:

• Need for Magnetic Shielding => They are incredibly sensitive to outside magnetic interference. To get an accurate reading, they must be put inside special, super-quiet "magnetic shields" that block out all other magnetic noise.  
• Lower Dynamic Range => They have a limited "dynamic range", work best only within a narrow range of magnetic field strengths.

What Is "Raman-Driven Spin Noise Spectroscopy (RDSNS)"?

It is an innovative method for measuring magnetic fields. Researchers at the Raman Research Institute (RRI) developed this technique.

It is a "quantum" method, uses the fundamental properties of atoms at their smallest level to make its measurements.

How does it work?

Shining Lasers => Researchers shine powerful laser light onto a collection of Rubidium atoms.

Listening to Jitters => The laser light acts like a highly sensitive microphone, picking up on the tiny, random wobbles (spin noise) of the atoms.

Detecting Shifts => When a magnetic field is present, it affects these atomic wobbles. The pattern of the spin noise shifts in predictable ways.  

Measuring the Field => By carefully analyzing these subtle shifts in the spin noise using the lasers, the researchers can accurately determine the strength of the magnetic field.  

Source: 

PIB