Magnetotransport in d-wave density waves

– Angle dependent magnetoresistance (ADMR) and giant Nernst effect are hallmarks of unconventional density waves (UDW). Here these transport properties for d-wave density wave (d-DW) are computed for quasi-two-dimensional systems. The present theory describes ADMR observed in the pseudogap phase of Y0.68Pr0.32Ba2Cu3O7 and CeCoIn5 single crystals very satisfactorily. Introduction. – As is well known, many electronic systems like high Tc cuprates, heavy fermion systems and organic conductors exhibit the pseudogap phenomenon or so-called nonFermi liquid behaviour [1]. Further, several people proposed that the pseudogap phase in the underdoped region of high Tc cuprates is d-wave density wave [2–4]. We have shown recently that the giant Nernst effect seen in the pseudogap region of LSCO, YBCO and Bi2212 [5–8] can be interpreted in terms of d-wave density wave (d-DW) [9]. Also the Pauli limiting behaviour of d-DW in the c-axis resistance [10, 11] indicates that it is d-wave charge density wave and not d-wave spin density wave [12]. Also there are many parallels between organic superconductor κ-(ET)2 salts [13], heavy fermion superconductor CeCoIn5 and high Tc cuprate superconductors. In particular the quasi-two-dimensional Fermi surface, the layered structure, d-wave superconductivity [14, 15] and the presence of pseudogap are noteworthy. Very recently d-DW in the pseudogap phase of CeCoIn5 was established through the giant Nernst effect [16, 17] and the angle dependent magnetoresistance [18]. As noted by Nersesyan et al. [19,20], the quasiparticle spectrum in unconventional density wave is quantized in a magnetic field. This Landau quantization gives rise to the spectacular angle dependent magnetoresistance (ADMR) and giant Nernst effect as reviewed in Ref. [21].