Terahertz radiation has uses in applications ranging from security to medicine. However, sensitive room-temperature detection of terahertz radiation is notoriously difficult. The hot-electron photothermoelectric effect in graphene is a promising detection mechanism; photoexcited carriers rapidly thermalize due to strong electron-electron interactions, but… (More)
We summarize the existing experimental data on electromagnons in multiferroic RMn 2 O 5 compounds, where R denotes a rare earth ion, Y or Bi, and discuss a realistic microscopic model of these materials based on assumption that the microscopic mechanism of magnetically-induced ferroelectricity and electromagnon absorption relies entirely on the isotropic… (More)
We report a large area terahertz detector utilizing a tunable plasmonic resonance in subwavelength graphene microribbons on SiC(0001) to increase the absorption efficiency. By tailoring the orientation of the graphene ribbons with respect to an array of subwavelength bimetallic electrodes, we achieve a condition in which the plasmonic mode can be… (More)
We report here a new type of plasmon resonance that occurs when graphene is connected to a metal. These new plasmon modes offer the potential to incorporate a tunable plasmonic channel into a device with electrical contacts, a critical step toward practical graphene terahertz optoelectronics. Through theory and experiments, we demonstrate, for example,… (More)
The spin-lattice coupling plays an important role in strongly frustrated magnets. In ZnCr2O4, an excellent realization of the Heisenberg antiferromagnet on the pyrochlore network, a lattice distortion relieves the geometrical frustration through a spin-Peierls-like phase transition at T(c)=12.5 K. Conversely, spin correlations strongly influence the elastic… (More)
Among its many outstanding properties, graphene supports terahertz surface plasma waves – sub-wavelength charge density oscillations connected with electromagnetic fields that are tightly localized near the surface[1, 2]. When these waves are confined to finite-sized graphene, plasmon resonances emerge that are characterized by alternating charge… (More)
Graphene has unique and advantageous electronic and optical properties, especially in the underdeveloped terahertz range of the electromagnetic spectrum[1–4]. Sub-micron graphene structures support terahertz (THz) plasmonic resonances that can be tuned by applying a gate voltage[5, 6]. Because these plasmonic structures are sub-wavelength in size, they need… (More)
The temporal response of a broadband, monolayer graphene photodetector based on the photothermoelectric effect is characterized. Pulse-coincidence and impulse response measurements indicate fast photodetection on the timescale of 10 ps.