Bose Metal

A research team from China and Japan has reported strong signs that niobium diselenide (NbSe₂) can become a Bose metal.

• About: The metals conduct electricity with finite conductivity, which changes with temperature.
• Superconductivity: Some metals, like zinc, exhibit infinite conductivity at very low temperatures due to Cooper pairs formation, leading to superconductivity.
• Bose Metal Concept: Some metals don’t become superconducting at low temperatures but still form Cooper pairs.

o These metals conduct electricity with Cooper pairs instead of electrons but fail to establish long-range superconducting coherence.

o This state is called a Bose metal, an anomalous metallic state (AMS).

• Scientific Importance: Challenges traditional theories predicting metals should be either insulators or superconductors at absolute zero.

o Helps in understanding disordered metals, which have irregular atomic structures, impurities, or alloyed formations.

• NbSe₂ & Bose Metal Study: NbSe₂ is a type-II superconductor, expelling magnetic fields but allowing them in isolated pockets.

o A 2D NbSe₂ layer under a specific magnetic field was studied, showing Cooper pairs without superconductivity.

o Hall resistance vanished, indicating Cooper pairs as charge carriers.