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Siddiqi I, Prober DE. Nb–Au bilayer hot-electron bolometers for low-noise THz heterodyne detection. Appl Phys Lett. 2004;84(8):1404.
Abstract: The sensitivity of present Nb diffusion-cooled hot-electron bolometer (HEB) mixers is not quantum limited, and can be improved by reducing the superconducting transition temperature TC. Lowering TC reduces thermal fluctuations, resulting in a decrease of the mixer noise temperature TM. However, lower TC mixers have reduced dynamic range and saturate more easily due to background noise. We present 30 GHz microwave measurements on a bilayer HEB system, Nb–Au, in which TC can be tuned with Au layer thickness to obtain the maximum sensitivity for a given noise background. These measurements are intended as a guide for the optimization of THz mixers. Using a Nb–Au mixer with TC = 1.6 K, we obtain TM = 50 K with 2 nW of local oscillator (LO) power. Good mixer performance is observed over a wide range of LO power and bias voltage and such a device should not exhibit saturation in a THz receiver.
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An Z, Chen J-C, Ueda T, Komiyama S, Hirakawa K. Infrared phototransistor using capacitively coupled two-dimensional electron gas layers. Appl Phys Lett. 2005;86:172106-3.
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Barends R, Hajenius M, Gao JR, Klapwijk TM. Current-induced vortex unbinding in bolometer mixers. Appl Phys Lett. 2005;87:263506 (1 to 3).
Abstract: We present a description of the current-voltage characteristics of hot electron bolometers in terms of the current-dependent intrinsic resistive transition of NbN films. We find that, by including this current dependence, we can correctly predict the complete current-voltage characteristics, showing excellent agreement with measurements for both low and high bias and for small as well as large devices. It is assumed that the current dependence is due to vortex-antivortex unbinding as described in the Berezinskii–Kosterlitz–Thouless theory. The presented approach will be useful in guiding device optimization for noise and bandwidth.
Keywords: HEB mixer numerical model, HEB model, IV-curves, vortex-antivortex, Berezinskii–Kosterlitz–Thouless theory, diffusion cooling channel, diffusion channel, distributed HEB model, distributed model, self-heating effect, temperature profile
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Hadfield RH, Habif JL, Schlafer J, Schwall RE, Nam SW. Quantum key distribution at 1550 nm with twin superconducting single-photon detectors. Appl Phys Lett. 2006;89(24):241129.
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Rodriguez-Morales F, Zannoni R, Nicholson J, Fischetti M, Yngvesson KS, Appenzeller J. Direct and heterodyne detection of microwaves in a metallic single wall carbon nanotube. Appl Phys Lett. 2006;89(8):083502.
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Stevens M, Hadfield R, Schwall R, Nam SW, Mirin R, Gupta J. Fast lifetime measurements of infrared emitters using a low-jitter superconduct- ing single-photon detector. Appl Phys Lett. 2006;89:031109.
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Walther C, Scalari G, Faist J, Beere H, Ritchie D. Low frequency terahertz quantum cascade laser operating from 1.6 to 1.8 THz. Appl Phys Lett. 2006;89:231121(1–3).
Abstract: The authors report a GaAs/Al0.1Ga0.9As quantum cascade laser based on a bound-to-continuum transition optimized for low frequency operation. High tunability of the gain curve is achieved by the Stark effect and laser emission is measured between 1.6 and 1.8 THz. Pulsed mode operation up to 95 K and continuous wave operation up to 80 K are reported. The dynamical range in current is as high as 43%.
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Baryshev A., Hovenier J.N., Adam A.J.L., Kašalynas I., Gao J.R., Klaassen T.O., et al. Phase locking and spectral linewidth of a two-mode terahertz quantum cascade laser. Physics Letters. 2006;89.
Abstract: We have studied the phase locking and spectral linewidth of an ~ 2.7 THz quantum cascade laser by mixing its two lateral lasing modes. The beat signal at about 8 GHz is compared with a microwave eference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in a narrow beat linewidth of less than 10 Hz. Under requency stabilization we find that the terahertz line profile is essentially Lorentzian with a minimum linewidth of ~ 6.3 kHz. Power dependent measurements suggest that this linewidth does not approach the Schawlow-Townes limit.
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Dorenbos SN, Reiger EM, Perinetti U, Zwiller V, Zijlstra T, Klapwijk TM. Low noise superconducting single photon detectors on silicon. Appl Phys Lett. 2008;93(13):131101.
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Fu K, Zannoni R, Chan C, Adams SH, Nicholson J, Polizzi E, et al. Terahertz detection in single wall carbon nanotubes. Appl Phys Lett. 2008;92(3):033105.
Abstract: It is reported that terahertz radiation from 0.69 to 2.54 THz has been sensitively detected in a device consisting of bundles of carbon nanotubes containing single wall metallic carbon nanotubes, quasioptically coupled through a lithographically fabricated antenna, and a silicon lens. The measured data are consistent with a bolometric detection process in the metallic tubes and the devices show promise for operation well above 4.2 K.
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