We introduce a generalized joint density of states(GJDOS),which incorporates the coherent factors into the JDOS,to study quasiparticle interference(QPI)in superconductors.The intimate relation between the Fourier-tran...We introduce a generalized joint density of states(GJDOS),which incorporates the coherent factors into the JDOS,to study quasiparticle interference(QPI)in superconductors.The intimate relation between the Fourier-transformed local density of states and GJDOS is revealed:they correspond respectively to the real and imaginary parts of a generalized impurity-response function,and particularly share the same angular factors and singular boundaries,as seen from our approximate analytic results for d-wave superconductors.Remarkably,our numerical GJDOS analysis agrees well with the QPI patten of d-wave cuprates and s_(±)-wave iron-based superconductors.Moreover,we illustrate that the present GJDOS scenario can uncover the sign features of the superconducting gap and thus can be used to explore the pairing symmetry of the A_(1-x)Fe_(2-y)Se_(2)(A=K,Cs,etc)superconductors.展开更多
基金the RGC of Hong Kong under Grant Nos HKU7055/09P and HKUST3/CRF/09the URC fund of HKU,and the National Natural Science Foundation of China under Grant No 11274379.
文摘We introduce a generalized joint density of states(GJDOS),which incorporates the coherent factors into the JDOS,to study quasiparticle interference(QPI)in superconductors.The intimate relation between the Fourier-transformed local density of states and GJDOS is revealed:they correspond respectively to the real and imaginary parts of a generalized impurity-response function,and particularly share the same angular factors and singular boundaries,as seen from our approximate analytic results for d-wave superconductors.Remarkably,our numerical GJDOS analysis agrees well with the QPI patten of d-wave cuprates and s_(±)-wave iron-based superconductors.Moreover,we illustrate that the present GJDOS scenario can uncover the sign features of the superconducting gap and thus can be used to explore the pairing symmetry of the A_(1-x)Fe_(2-y)Se_(2)(A=K,Cs,etc)superconductors.
