Quantum Hall Effect
The Quantum Hall Effect is a phenomenon in condensed matter physics that occurs when a two-dimensional electron gas is subjected to a strong magnetic field perpendicular to its plane. It results in the quantisation of the Hall resistance. The Quantum Hall Effect has found several groundbreaking applications, primarily in precision metrology. Its quantised nature allows for the accurate definition of the ohm, the unit of electrical resistance. This has led to the redefinition of the international standard for resistance. Additionally, the Quantum Hall Effect has enabled the creation of highly accurate resistance standards used in calibrating instruments, and its principles have been leveraged in the development of highly sensitive magnetometers and sensors for fields such as materials science, electronics, and quantum research.