Resistive transition of niobium superconducting hot-electron bolometer mixers

We present a model for the description of the resistive transition in hot-electron bolometer mixers. We show that the transition is a property of a superconducting microbridge connected to normal conducting cooling pads. Using the concepts of the superconducting proximity effect, charge-imbalance generation, and Andreev reflection, we have calculated the resistance versus temperature of the device and demonstrate its dependence on the length of the microbridge, both theoretically and experimentally. The analysis reopens the question of the relationship between the resistive transition and the situation in which the device is optimally operated as a heterodyne mixer.

[1]  Michael Tinkham,et al.  Introduction to Superconductivity , 1975 .

[2]  J. Clarke,et al.  Boundary resistance of the superconducting-normal interface , 1980 .

[3]  Sigfrid Yngvesson,et al.  Gain and noise bandwidth of NbN hot-electron bolometric mixers , 1997 .

[4]  Anders Skalare,et al.  Length scaling of bandwidth and noise in hot‐electron superconducting mixers , 1996 .

[5]  M. Beasley,et al.  Phase-slip centers and nonequilibrium processes in superconducting tin microbridges , 1974 .

[6]  Boris S. Karasik,et al.  Low noise in a diffusion-cooled hot-electron mixer at 2.5 THz , 1997 .

[7]  Daniel E. Prober,et al.  Superconducting terahertz mixer using a transition-edge microbolometer , 1993 .

[8]  J. Clarke,et al.  Theory of Pair-Quasiparticle Potential Difference in Nonequilibrium Superconductors , 1972 .

[9]  T. M. Klapwijk,et al.  Transition from metallic to tunneling regimes in superconducting microconstrictions: Excess current, charge imbalance, and supercurrent conversion , 1982 .

[10]  D. Prober,et al.  Inelastic electron scattering mechanisms in clean aluminum films , 1984 .

[11]  Boris S. Karasik,et al.  Noise temperature limit of a superconducting hot‐electron bolometer mixer , 1996 .

[12]  Anders Skalare,et al.  Large Bandwidth and Low Noise in a Diffusion-Cooled Hot-Electron Bolometer Mixer , 1996 .

[13]  A. Skalare,et al.  Receiver measurements at 1267 GHz using a diffusion-cooled superconducting transition-edge bolometer , 1997, IEEE Transactions on Applied Superconductivity.