Researchers have demonstrated a low-cost digital system to efficiently measure unknown magnetic fields.
Context
Researchers have demonstrated a low-cost digital system to efficiently measure unknown magnetic fields.
About the newly developed magnetometer
Magnetometer is a device that measures magnetic field or magnetic dipole moment.
- Working of magnetometer: The magnetic matter creates digital signals which are analysed for the properties such as their time duration.
- These signals are received through the hardware of digital receiver systems, which are built with standard silicon-based memory devices.
Digital signals
- Digital signals are the backbone of communication systems processed by hardware systems.
- They transmit and receive the signals with the help of intermediate systems called ‘digital receiver systems’ or DRS.
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- Computer codes are implemented for these devices to perform mathematical operations.
- On the signal they receive, enabling DRS systems to measure fundamental properties of matter like ‘Spin’.
Spin of electrons
- The spin of electrons determines the magnetism of most of the objects around us.
- The electrons’ spin is not constant at room temperatures.
- These spin fluctuations cause what scientists call ‘spin-noise’.
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- By measuring the tiny fluctuations in the magnetic field, the researchers can infer the spin-noise accurately.
How the research was conducted?
- Rubidium atoms were heated to temperatures ranging between 100 and 200 degrees Celsius, causing spin fluctuations.
- They bombarded the atoms with a laser, which has a property called ‘polarization’.
- The spin fluctuations caused the laser’s polarization to fluctuate, which the researchers measured using a light detector.
- The polarization fluctuation is the signal for the digital receiver system.
- They designed the system to work in two different modes.
- One of them uses a widely-used mathematical function, the ‘Fourier transform’ of the signal, named after its inventor Joseph Fourier.
- The Fourier transform of the signal lets them calculate how the rubidium atom’s energies vary, from which they can directly infer the magnetic field.
- A standard method of measuring the magnetic field analyses small frequency ranges of the signal separately.
- Significance of the new magnetometer: The researchers showed that the new method speeds up the calculations compared to the standard method.
- Their improved method also increased their confidence in how the electrons’ energies vary more than ten times.
- The study was supported by the Department of Science and Technology and the Ministry of Electronics and Information Technology (MeitY) Government of India.
