| |
Records |
Links |
|
Author |
Yang, Y.; Fedorov, G.; Shafranjuk, S. E.; Klapwijk, T. M.; Cooper, B. K.; Lewis, R. M.; Lobb, C. J.; Barbara, P. |
|
| |
Title |
Electronic transport and possible superconductivity at Van Hove singularities in carbon nanotubes |
Type |
Journal Article |
| |
Year |
2015 |
Publication |
Nano Lett. |
Abbreviated Journal |
Nano Lett. |
|
| |
Volume |
15 |
Issue |
12 |
Pages |
7859-7866 |
|
| |
Keywords |
carbon nanotubes, CNT, tunable superconductivity, van Hove singularities |
|
| |
Abstract |
Van Hove singularities (VHSs) are a hallmark of reduced dimensionality, leading to a divergent density of states in one and two dimensions and predictions of new electronic properties when the Fermi energy is close to these divergences. In carbon nanotubes, VHSs mark the onset of new subbands. They are elusive in standard electronic transport characterization measurements because they do not typically appear as notable features and therefore their effect on the nanotube conductance is largely unexplored. Here we report conductance measurements of carbon nanotubes where VHSs are clearly revealed by interference patterns of the electronic wave functions, showing both a sharp increase of quantum capacitance, and a sharp reduction of energy level spacing, consistent with an upsurge of density of states. At VHSs, we also measure an anomalous increase of conductance below a temperature of about 30 K. We argue that this transport feature is consistent with the formation of Cooper pairs in the nanotube. |
|
| |
Address |
Department of Physics, Georgetown University , Washington, District of Columbia 20057, United States |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN  |
1530-6984 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:26506109; Suuplementary info (attached to pdf) DOI: 10.1021/acs.nanolett.5b02564 |
Approved |
no |
|
| |
Call Number |
|
Serial |
1782 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Colombelli, R |
|
| |
Title |
FIR quantum cascade lasers at λ>20 μm and THz emitters at λ=80 μm |
Type |
Journal Article |
| |
Year |
2002 |
Publication |
Phys. E: Low-dimensional Systems and Nanostructures |
Abbreviated Journal |
|
|
| |
Volume |
13 |
Issue |
2-4 |
Pages |
848-853 |
|
| |
Keywords |
|
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1386-9477 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
483 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hübers, H.-W.; Schubert, J.; Krabbe, A.; Birk, M.; Wagner, G.; Semenov, A.; Gol’tsman, G.; Voronov, B.; Gershenzon, E. |
|
| |
Title |
Parylene anti-reflection coating of a quasi-optical hot-electron-bolometric mixer at terahertz frequencies |
Type |
Journal Article |
| |
Year |
2001 |
Publication |
Infrared Physics & Technology |
Abbreviated Journal |
Infrared Physics & Technology |
|
| |
Volume |
42 |
Issue |
1 |
Pages |
41-47 |
|
| |
Keywords |
NbN HEB mixers, anti-reflection coating |
|
| |
Abstract |
Parylene C was investigated as anti-reflection coating for silicon at terahertz frequencies. Measurements with a Fourier-transform spectrometer show that the transmittance of pure silicon can be improved by about 30% when applying a layer of Parylene C with a quarter wavelength optical thickness. The 10% bandwidth of this coating extends from 1.5 to 3 THz for a center frequency of 2.3–2.5 THz, where the transmittance is constant. Heterodyne measurements demonstrate that the noise temperature of a hot-electron-bolometric mixer can be reduced significantly by coating the silicon lens of the hybrid antenna with a quarter wavelength Parylene C layer. Compared to the same mixer with an uncoated lens the improvement is about 30% at a frequency of 2.5 THz. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1350-4495 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1548 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gol'tsman, G. N. |
|
| |
Title |
Hot electron bolometric mixers: new terahertz technology |
Type |
Journal Article |
| |
Year |
1999 |
Publication |
Infrared Physics & Technology |
Abbreviated Journal |
Infrared Physics & Technology |
|
| |
Volume |
40 |
Issue |
3 |
Pages |
199-206 |
|
| |
Keywords |
NbN HEB mixers |
|
| |
Abstract |
This paper presents an overview of recent results for NbN phonon-cooled hot electron bolometric (HEB) mixers. The noise temperature of the receivers based on both quasioptical and waveguide versions of HEB mixers has crossed the level of 1 K GHz−1 at 430 GHz (410 K), 600–650 GHz (480 K), 750 GHz (600 K), 810 GHz (780 K) and is close to that level at 1.1 THz (1250 K) and 2.5 THz (4500 K). The gain bandwidth measured for quasioptical HEB mixer at 620 GHz reached 4 GHz and the noise temperature bandwidth was almost 8 GHz. Local oscillator power requirements are about 1 μW for mixers made by photolithography and about 100 nW for mixers made by e-beam lithography. A waveguide version of 800 GHz receiver was installed at the Submillimeter Telescope Observatory on Mt. Graham, AZ, to conduct astronomical observations of known submillimeter lines (CO, J=7→6, CI, J=2→1). It was proved that the receiver works as a practical instrument. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1350-4495 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1570 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Semenov, A.; Engel, A.; Il'in, K.; Gol'tsman, G.; Siegel, M.; Hübers, H.-W. |
|
| |
Title |
Ultimate performance of a superconducting quantum detector |
Type |
Journal Article |
| |
Year |
2003 |
Publication |
Eur. Phys. J. Appl. Phys. |
Abbreviated Journal |
Eur. Phys. J. Appl. Phys. |
|
| |
Volume |
21 |
Issue |
3 |
Pages |
171-178 |
|
| |
Keywords |
NbN SSPD, SNSPD |
|
| |
Abstract |
We analyze the ultimate performance of a superconducting quantum detector in order to meet requirements for applications in near-infrared astronomy and X-ray spectroscopy. The detector exploits a combined detection mechanism, in which avalanche quasiparticle multiplication and the supercurrent jointly produce a voltage response to a single absorbed photon via successive formation of a photon-induced and a current-induced normal hotspot in a narrow superconducting strip. The response time of the detector should increase with the photon energy providing energy resolution. Depending on the superconducting material and operation conditions, the cut-off wavelength for the single-photon detection regime varies from infrared waves to visible light. We simulated the performance of the background-limited infrared direct detector and X-ray photon counter utilizing the above mechanism. Low dark count rate and intrinsic low-frequency cut-off allow for realizing a background limited noise equivalent power of 10−20 W Hz−1/2 for a far-infrared direct detector exposed to 4-K background radiation. At low temperatures, the intrinsic response time of the counter is rather determined by diffusion of nonequilibrium electrons than by the rate of energy transfer to phonons. Therefore, thermal fluctuations do not hamper energy resolution of the X-ray photon counter that should be better than 10−3 for 6-keV photons. Comparison of new data obtained with a Nb based detector and previously reported results on NbN quantum detectors support our estimates of ultimate detector performance. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1286-0042 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
534 |
|
| Permanent link to this record |
