James E Tate
Summary
James E. Tate is an American experimental physicist who, while at Stanford in the late 1980s, conducted high-precision measurements of the Cooper-pair effective mass in rotating superconducting niobium rings. The results (Tate et al. 1989, 1990) showed an apparent anomaly: the measured Cooper-pair mass exceeded the standard BCS prediction by approximately 80 parts per million — a discrepancy never satisfactorily resolved and frequently cited in the gravitomagnetic-superconductor literature.
Life
Tate completed his physics PhD at Stanford in the late 1980s, working with Blas Cabrera (the magnetic-monopole detector physicist) on precision low-temperature measurements. After Stanford he moved to other research positions; his subsequent publication record is sparse in the public archive.
Key Contributions
Cooper-pair mass measurement
The Tate-Cabrera-Felch-Anderson 1989 Physical Review B 39: 11600 paper and follow-up Tate 1990 Physical Review Letters 65: 1418 reported precision measurements of the rotational magnetic moment of superconducting niobium rings. The measurement determines the Cooper-pair effective mass through the London moment relation.
The result: m*/me = 1.000084(21) — approximately 84 parts per million higher than the BCS-theoretical prediction of m* = 2me (or, more carefully, the BCS-corrected prediction of m* = 1.999963 me).
The discrepancy is ~ 4σ from zero. Subsequent theoretical work (Liu 1998, others) has proposed various conventional explanations (lattice contributions, finite-size effects) but the discrepancy has not been definitively resolved.
The anomaly has been adopted by the gravitomagnetic-superconductor research programme as candidate evidence for the Li-Torr / Tajmar / Modanese predictions.
Reception
The Tate measurements are mainstream-published, precision-physics work. The anomaly is real (in the sense of being statistically significant) but its interpretation is contested. Mainstream condensed-matter physics treats the discrepancy as a precision-measurement puzzle awaiting better theoretical understanding; alternative-physics communities treat it as suggestive evidence for non-standard gravitational effects.
Bibliography
- Tate, J., Cabrera, B., Felch, S. B., Anderson, J. T. (1989). "Precise determination of the Cooper-pair mass." Physical Review B 39: 11600.
- Tate, J. (1990). "Determination of the Cooper-pair mass in niobium." Physical Review Letters 65: 1418.
See Also
External Links
- Stanford Physics archive.
References
- As above.
