Abstract
While Josephson-like junctions, transiently established in heavy-ion collisions () between superfluid nuclei—and through which Cooper-pair tunneling (-value ) proceeds mainly in terms of successive transfer of entangled nucleons—are deprived of the macroscopic aspects of a supercurrent, they display many of the special effects associated with spontaneous symmetry breaking in gauge space (BCS condensation), which can be studied in terms of individual quantum states and of tunneling of single Cooper pairs. From the results of studies of one- and two-neutron transfer reactions carried out at energies below the Coulomb barrier we estimate the value of the mean-square radius (correlation length) of the nuclear Cooper pair. A quantity related to the largest distance of closest approach for which the absolute two-nucleon tunneling cross section is of the order of the single-particle one. Furthermore, emission of rays of (Josephson) frequency distributed over an energy range is predicted.
- Received 13 October 2020
- Accepted 19 November 2020
- Corrected 22 April 2021
- Corrected 14 March 2022
DOI:https://doi.org/10.1103/PhysRevC.103.L021601
©2021 American Physical Society
Physics Subject Headings (PhySH)
Corrections
22 April 2021
Correction: The first sentence of the abstract contained a syntax error and has been fixed to achieve clarity.
14 March 2022
Second Correction: The inline equation at the end of the sixth sentence of the fourth paragraph contained an error and has been set right.
Viewpoint
The Tiniest Superfluid Circuit in Nature
Published 25 February 2021
A new analysis of heavy-ion collision experiments uncovers evidence that two colliding nuclei behave like a Josephson junction—a device in which Cooper pairs tunnel through a barrier between two superfluids.
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