Angle-Resolved Photoemission Spectroscopy Study of Spin Fluctuations in the Cuprate Superconductors

This thesis makes significant advances towards an understanding of superconductivity in the cuprate family of unconventional, high-temperature superconductors. It suggests that collective magnetic excitations of the conduction electrons could lead them to form pairs, which in turn condense to form the superconducting state at a critical temperature Tc. Quantitative calculations of Tc using experimental data were not available to verify the applicability of this magnetic mechanism. The author constructed an angle-resolved photoemission apparatus and applied the Bethe-Salpeter method to his unusual pristine and precise normal state data, leading to the conclusion that antiferromagnetic correlations are a viable candidate for the pairing interaction in the cuprate superconductors.

Format: Hardback
Length: 104 pages
Publication date: 14 September 2022
Publisher: Springer International Publishing AG

This thesis makes significant strides towards an understanding of superconductivity in the cuprate family of unconventional, high-temperature superconductors. Despite the discovery of high-temperature superconductors over 35 years ago, there is still no widely accepted theory of superconductivity in these materials. One early proposal suggested that collective magnetic excitations of the conduction electrons could lead them to form pairs, which in turn condense to form the superconducting state at a critical temperature Tc. However, quantitative calculations of Tc using experimental data were not available to verify the applicability of this magnetic mechanism.

In this thesis, the author constructed an angle-resolved photoemission apparatus that could provide sufficiently accurate data of the electronic excitation spectra of samples in the normal state, data that was further unusually devoid of any surface contamination. The author also applied the Bethe-Salpeter method to his exceptionally pristine and precise normal state data, and was able to predict the approximate superconducting transition temperatures of different samples. This rare combination of experiment with sophisticated theoretical calculations leads to the conclusion that antiferromagnetic correlations are a viable candidate for the pairing interaction in the cuprate superconductors.

Furthermore, the author's research suggests that the superconducting state in the cuprate superconductors is characterized by a phase transition from a normal state with antiferromagnetic correlations to a superconducting state with paired electrons. This transition is driven by the suppression of antiferromagnetic correlations, which leads to the formation of Cooper pairs. The author's work provides a new understanding of the pairing mechanism in the cuprate superconductors and has implications for the development of new high-temperature superconductors and other related materials.

In conclusion, this thesis makes significant contributions to our understanding of superconductivity in the cuprate family of unconventional, high-temperature superconductors. The author's innovative experimental and theoretical approach provides a new understanding of the pairing mechanism and has implications for the development of new high-temperature superconductors and other related materials.

Weight: 354g
Dimension: 235 x 155 (mm)
ISBN-13: 9783031109782
Edition number: 1st ed. 2022