Christopher B. McKitterick, Heli Vora, Xu Du, Boris S. Karasik and Daniel E. Prober
Christopher B. McKitterick
Daniel E. Prober at Departments of Physics and Applied Physics, Yale University, New Haven, Connecticut 06520, USA (email: chris.mckitterick@yale.edu) (email: daniel.prober@yale.edu)
Heli Vora
Xu Du at Department of Physics, Stony Brook University, Stony Brook, New York 11790, USA
Boris S. Karasik at Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
http://eprintweb.org/S/article/cond-mat/1307.5012
Abstract. We report on noise and thermal conductance measurements taken in order to determine an upper bound on the performance of graphene as a terahertz photon detector. The main mechanism for sensitive terahertz detection in graphene is bolometric heating of the electron system. To study the properties of a device using this mechanism to detect terahertz photons, we perform Johnson noise thermometry measurements on graphene samples. These measurements probe the electron-phonon behavior of graphene on silicon dioxide at low temperatures. Because the electron-phonon coupling is weak in graphene, superconducting contacts with large gap are used to confine the hot electrons and prevent their out-diffusion. We use niobium nitride leads with a $T_mathrmcapprox 10$ K to contact the graphene. We find these leads make good ohmic contact with very low contact resistance. Our measurements find an electron-phonon thermal conductance that depends quadratically on temperature above 4 K and is compatible with single terahertz photon detection.
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