2001/01/01 by M. Windt, M. Grüninger, M. Grueninger +16 · 5 citations
Business, Management and Accounting · Materials Science · Physics and Astronomy · Social Sciences · #Advanced Condensed Matter Physics #Condensed matter physics #Cuprate #Fermion #Ferromagnetism #Higher Education Teaching and Evaluation #Humanities #Magnetic and transport properties of perovskites and related materials #Magnon #Omega #Organizational Management and Innovation #Perturbation theory (quantum mechanics) #Philosophy #Physics #Physics of Superconductivity and Magnetism #Political science #Quantum mechanics #Sociology #Spin (aerodynamics) #Superconductivity #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.87.127002
published as Phys. Rev. Lett. 87, 127002 (2001) · 4 pages, 3 figures, Revtex
openalex publication_date 2001/01/01 · arxiv created 2001/03/21 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/04/28
Phonon-assisted two-magnon absorption is studied in the spin- 1/2 two-leg ladders of (Ca,La)(14)Cu(24)O(41) for E parallel c (legs) and E parallel a (rungs). We verify the theoretically predicted existence of two-magnon singlet bound states, which give rise to peaks at approximately equal to 2140 and 2800 cm(-1). The two-magnon continuum is observed at approximately equal to 4000 cm(-1). Two different theoretical approaches (Jordan-Wigner fermions and perturbation theory) describe the data very well for J parallel approximately equal to 1020-1100 cm(-1), J parallel/J perpendicular approximately equal to 1-1.2. At high energies, the magnetic contribution to sigma(omega) is strikingly similar in the ladders and in the undoped high-T(c) cuprates, which emphasizes the importance of strong quantum fluctuations in the latter.