Cooper electron pair

physics

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June 24, 2026

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In physics, a Cooper pair is a pair of electrons in a superconductor that are bound together and have opposite momentum and spin. This pairing is a key concept in the BCS theory, which explains superconductivity – the phenomenon where certain materials lose all electrical resistance when cooled below a specific transition temperature, typically near absolute zero.123

When a voltage is applied to a superconductor, all Cooper pairs move together, creating an electric current that can flow indefinitely without opposition because the pairs do not scatter. As the material warms, the Cooper pairs separate into individual electrons, and the material returns to its normal, nonsuperconducting state. The energy associated with this electron ordering is very small.24

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BCS theory
…grouped in pairs, now called Cooper pairs, and that the motions of all of the Cooper pairs within a single superconductor are correlated; they constitute a system that functions as a single entity. Application of an electrical voltage to the superconductor causes all Cooper pairs to move, constituting a current.…
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…grouped in pairs, now called Cooper pairs, and that the motions of all of the Cooper pairs within a single superconductor are correlated; they constitute a system that functions as a single entity. Application of an electrical voltage to the superconductor causes all Cooper pairs to move, constituting a current.…
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Leon N. Cooper
The concept of Cooper electron pairs was named after him.
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The concept of Cooper electron pairs was named after him.
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Josephson effect
…of pairs of electrons called Cooper pairs. According to Josephson, under certain circumstances these Cooper pairs move from one superconductor to the other across the thin insulating layer. Such motion of pairs of electrons constitutes the Josephson current, and the process by which the pairs cross the insulating layer is…
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…of pairs of electrons called Cooper pairs. According to Josephson, under certain circumstances these Cooper pairs move from one superconductor to the other across the thin insulating layer. Such motion of pairs of electrons constitutes the Josephson current, and the process by which the pairs cross the insulating layer is…
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