Does the charge-transfer gap set the maximum T_c across cuprate families? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title · changed
Revision 1: Does the charge-transfer gap set the maximum $T_{c}$ across cuprate families
Revision 2: Does the charge-transfer gap set the maximum $T_{c}$ across cuprate families?
Plain
The energy needed to move an electron from oxygen to copper, the charge-transfer gap, differs between cuprate families; superexchange theories predict that a smaller gap gives stronger pairing and a higher transition temperature.
Precise · changed · core
Revision 1: For hole-doped cuprates at optimal doping, test whether T_c,max and the zero-temperature pair density decrease monotonically with the charge-transfer energy $\Delta_{\mathrm{CT}}$ (equivalently increase with $J\sim t_{\mathrm{pd}}^4/\Delta_{\mathrm{CT}}^3$), as superexchange pairing in the three-band Emery model predicts. An answer is a cross-family data set ($\Delta_{\mathrm{CT}}$ from optics or tunneling, T_c,max, superfluid density) with a quantitative fit to model predictions, or a counterexample family.
Revision 2: For hole-doped cuprates at optimal doping, test whether $T_c,\mathrm{max}$ and the zero-temperature pair density decrease monotonically with the charge-transfer energy $\Delta_{\mathrm{CT}}$ (equivalently increase with $J\sim t_{\mathrm{pd}}^4/\Delta_{\mathrm{CT}}^3$), as superexchange pairing in the three-band Emery model predicts. An answer is a cross-family data set ($\Delta_{\mathrm{CT}}$ from optics or tunneling, $T_c,\mathrm{max}$, superfluid density) with a quantitative fit to model predictions, or a counterexample family.
Settled by
Measurement of $\Delta_{\mathrm{CT}}$ and the pair or superfluid density in at least five cuprate families, compared with three-band model calculations of $T_{c}$ versus $\Delta_{\mathrm{CT}}$.
Kind
well-posed
Answer type
yes-no
References
(empty)
Literature status
partially-resolved
Status note
Scanning tunneling spectroscopy on Bi2Sr2CaCu2O8+x (2022) found that the local pair density anticorrelates with the local charge-transfer gap; a cross-family quantitative test is incomplete.
Posed since
(empty)

Decisions