Superconductivity

A number of characteristic phenomena related to the superconductivity can be investigated using terahertz and infrared spectroscopy. This includes such fundamental features as energy gap and the dynamics of the charge carriers. Another interesting properties are:

  • transversal and longitudinal plasma resonances (Sm(La:Sr)CuO4)
  • mixed ac-excitations ((Nd:Ce)CuO4, (La:Ce)CuO4)
  • quasiparticle relaxation rates

Coherence peak in MgB2
Symbols - experiment. Solid line - BCS model with 2Δ/kBTc = 3.53.
Coherence Peak in MgB2
Superconducting gap in MgB2
Superconducting gap in MgB2
In this case the gap can be seen directly in the spectra. Lines data measured directly using Fourier-Transform spectrometer. Symbols - reflectance as calculated from the results of transmittance experiments using terahertz spectrometer. Note: The conductivity experiments are sensitive to an onset of the absorption, which therefore corresponds to the lowest gap in MgB2. [Ref]

Selected publications

  • M. Dressel, N. Drichko, B. Gorshunov, and A. Pimenov
    THz Spectroscopy of Superconductors
    IEEE Selected Topics in Quantum Electronics 14, 399 (2008) 
  • A. V. Pronin, A. Pimenov, A. Loidl, A. Tsukada, and M. Naito
    Doping dependence of the gap anisotropy in electron-doped superconductor La2-xCexCuO4
    Phys. Rev. B 68, 054511 (2003) 
  • A. Pimenov, A. V. Pronin, A. Loidl, A. Tsukada, and M. Naito
    Far-infrared and submillimeter-wave conductivity in electron-doped cuprate La2-xCexCuO4
    Europhysics Lett. 64, 246 (2003)
  • A. Pimenov, A. V. Pronin, A. Loidl, A. Tsukada, and M. Naito
    On the peak in the far-infrared conductivity of strongly anisotropic cuprates
    Phys. Rev B 66, 212508 (2002)
  • A. Pimenov
    Infrared conductivity and Superconducting Energy Gap in MgB2
    Adv. in Solid State Phys. 42, 267 (2002)
  • A. Pimenov, A. Loidl, and S. I. Krasnosvobodtsev
    Superconducting energy gap in MgB2 film observed by infrared reflectance
    Phys. Rev. B 65, 172502 (2002)
  • A. Pimenov, A. Loidl, D. Dulic, D. van der Marel, I. M. Sutjahja, and A. A. Menovsky
    Magnetic Field Dependence of the Transverse Plasmon in SmLa0.8Sr0.2CuO4
    Phys. Rev. Lett. 87, 177003, (2001)
  • A. V. Pronin, A. Pimenov, A. Loidl, and S. I. Krasnosvobodtsev
    Optical conductivity and penetration depth in MgB2
    Phys. Rev. Lett. 87, 097003 (2001)
  • D. Dulic, A. Pimenov, D. van der Marel, D. M. Broun, Saeid Kamal, W.N. Hardy, A.A. Tsvetkov, I.M. Sutjaha, R. Liang, A.A. Menovsky, A. Loidl, and S.S. Saxena
    Observation of the Transverse Optical Plasmon in SmLa0.8Sr0.2CuO4
    Phys. Rev. Lett. 86, 4144 (2001)
  • A. Pimenov, A. V. Pronin, A. Loidl, A. Kampf, S. I. Krasnosvobodtsev, and V. S. Nozdrin
    Submillimeter spectroscopy of tilted Nd1.85Ce0.15CuO4 films: observation of a mixed ac-plane excitation
    Appl. Phys. Lett. 77, 429 (2000)
  • A. Pimenov, A. Loidl, B. Shey, B. Stritzker, G. Jakob, H. Adrian, A. V. Pronin, and Yu. G. Goncharov
    Universal relationship between conductivity and penetration depth in YBaCuO
    Europhys. Lett. 48, 73 (1999)
  • A. Pimenov, A. Loidl, G. Jakob, H. Adrian
    Optical conductivity in YBa2Cu3O7 thin films
    Phys. Rev. B 59,  4390 (1999)
  • A. V. Pronin, M. Dressel, A. Pimenov, A. Loidl, I. Roshchin, and L. H. Greene
    Direct observation of the superconducting energy gap developing in the conductivity spectra of niobium
    Phys. Rev. B 57, 14416 (1998)