Even and odd-frequency pairing correlations in 1-D t-J-h model: a comparative study

TL;DR

This paper introduces an equal-time odd-frequency pairing concept in a 1D t-J model, analyzing its correlations alongside BCS pairing, and finds that odd-frequency correlations can become significant under certain parameters.

Contribution

It presents a novel equal-time formulation of odd-frequency pairing in the t-J model and compares its correlations with BCS pairing in a 1D system.

Findings

Odd-frequency correlations become comparable to BCS correlations in certain parameter ranges.

Composite operators for Cooper pairs with magnetization fluctuations naturally emerge in the approach.

Spin and density fluctuations may enhance odd-gap susceptibilities in frustrated models.

Abstract

An equal time version of odd-frequency pairing for a generalized $t-J$ model is introduced. It is shown that the composite operators describing binding of Cooper pairs with magnetization fluctuations naturally appear in this approach. The pairing correlations in both BCS and odd-frequency channels are investigated exactly in 1D systems with up to 16 sites. Our results indicate that at some range of parameters odd-frequency correlations become comparable, however smaller than BCS pairing correlations. It is speculated that the spin and density fluctuations in the frustrated model lead to the enhancement of the odd gap susceptibilities. 4 postscript figure files are attached at the bottom of the tex file.