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Measuring the gap in ARPES experiments

A. A. Kordyuk·S. V. Borisenko·M. Knupfer·J. Fink
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Abstract

Angle-resolved photoemission spectroscopy (ARPES) is considered as the only experimental tool from which the momentum distribution of both the superconducting and pseudo-gap can be quantitatively derived. The binding energy of the leading edge of the photoemission spectrum, usually called the leading edge gap (LEG), is the model-independent quantity which can be measured in the modern ARPES experiments with the very high accuracy--better than 1 meV. This, however, may be useless as long as the relation between the LEG and the real gap is unknown. We present a systematic study of the LEG as a function of a number of physical and experimental parameters. The absolute gap values which have been derived from the numerical simulation prove, for example that the nodal direction in the underdoped Bi-2212 in superconducting state is really the node--the gap is zero. The other consequences of the simulations are discussed.

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A. A. Kordyuk, S. V. Borisenko, M. Knupfer, J. Fink. 2002-08-21. Measuring the gap in ARPES experiments. https://doi.org/10.1103/physrevb.67.064504

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