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Figure 7 | EPJ Quantum Technology

Figure 7

From: Few-qubit quantum-classical simulation of strongly correlated lattice fermions

Figure 7

The retarded impurity Green function and self-energy in the frequency domain. (a) The residues and poles of the Green function can be obtained from a fit of the form in Eq. (34) (red dashed line) to the \(G^{R}_{\mathrm{imp}}(\tau)\) data from the XY method with 24 Trotter steps (blue diamonds). (b) The real part of the impurity Green function, \(\operatorname{Re} [ G^{R}_{\mathrm{imp}}(\omega+i\eta) ]\) (blue line), with residues and poles obtained from the fit from (a), compared to the exact Green function (red dashed line). (c) Same as in (b), but for the self-energy \(\operatorname{Re} [ \Sigma_{\mathrm{imp}}(\omega+i\eta) ]\). We set \(U=4t^{*}\) and \(V=t^{*}\). In (b) and (c), we have broadened the peaks with \(\eta=0.01\) for clarity.

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