Externally phase-locked flux flow oscillator for submm integrated receivers: achievements and limitations

Koshelets, V. P.; Shitov, S. V.; Дмитриев, П. Н.; Ermakov, A. N.; Соболев, А. С.; Torgashin, M. Yu.; Khodos, V.V.; Вакс, В. Л.; Wesselius, P. R.; Yagoubov, P.; Mahaini, C.; Mygind, J.

doi:10.1109/tasc.2003.814144

Cited by 11 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8,9,45,46 We irradiated one five-junction array with microwaves at f rf Ϸ 600 GHz, i.e., slightly below the n = 3 resonant step's maximum at f 3 = V 3 / ⌽ 0 = 636 GHz. 7, the current locking range ⌬I = I + − I − varies linearly with the rf field amplitude ͱ P. This phase-lock mechanism looks very similar to rf phase-locking of fluxons previously reported in LJJs, both in resonant 13,30 and flux-flow 19,22,32 regimes, and occasionally in Josephson lattices. 38 The ϳ600 GHz solid-state source was a Gunn oscillator at ϳ100 GHz cascaded by a Schottky-diode ϫ6 frequency multiplier.…”

Section: B Submillimeter-wave Phase-lockingsupporting

confidence: 84%

“…14,18,19 In a DJTL, this criterion translates to The condition for a LJJ to enter the flux-flow regime is ␣l / J Ͼ 2.…”

Section: B Ffosmentioning

confidence: 99%

“…This type of dynamical regimes in LJJs was extensively studied by many groups theoretically 6-10 and experimentally, [11][12][13][14][15][16][17][18][19] largely due to the quest for Josephson millimeter-wave-to-terahertz clocks 20 and solid-state local oscillator sources. 1͑b͔͒.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fluxon modes and phase-locking at 600 GHz in superconducting tunnel junction nonuniform arrays

Salez

Boussaha

2010

Journal of Applied Physics

View full text Add to dashboard Cite

We investigated parallel arrays of superconducting Nb/ AlO x / Nb tunnel junctions nonevenly distributed in a superconducting Nb/SiO/Nb microstrip transmission line. Such devices are discretized Josephson transmission lines ͑DJTLs͒ in which, from theory, magnetic flux quanta ͑"fluxons"͒ can travel as solitonic waves when a dc current bias and a dc magnetic field are applied. We observed a reproducible series of resonant branches in each device's I − V curve, at Josephson submillimeter-wave frequencies ͑from 240 to 720 GHz͒ matching the resonances predicted using a transmission line analysis, where the loading of the N = 5 junctions is fully taken into account. The nonperiodic distribution was optimized to provide rf matching over a large bandwidth ͑450-650 GHz typically͒, implying that the plasma resonance of junctions is inductively tuned out over a similar band by the array. A confirmation of this comes from the observation, at frequencies higher than the untuned junctions plasma frequency, of several Josephson phenomena reported in this article: Fiske-like resonances, phase-locking of the n = 3 resonance to an external 600 GHz microwave source, rf-induced zero crossing, and resonances at fractional harmonics of the rf signal. These experimental results are all compatible with a fluxon-based resonances interpretation, as in the extensively studied long Josephson junctions yet at higher frequencies. As reported elsewhere, we could detect ϳ500 GHz microwave radiation emitted by our devices in the n = 1 and n =3 modes. In light of these unique properties, we propose nonuniform DJTLs as a promising type of Josephson device for submillimeter-wave oscillators and fast fluxon-based electronics.

show abstract

Section: B Submillimeter-wave Phase-lockingsupporting

confidence: 84%

“…14,18,19 In a DJTL, this criterion translates to The condition for a LJJ to enter the flux-flow regime is ␣l / J Ͼ 2.…”

Section: B Ffosmentioning

confidence: 99%

See 1 more Smart Citation

Fluxon modes and phase-locking at 600 GHz in superconducting tunnel junction nonuniform arrays

Salez

Boussaha

2010

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…It is interesting at this point to refer to an alternative type of superconducting Josephson-effect oscillator which has been thoroughly investigated in recent years: the Josephson FluxFlow Oscillator (FFO) [11]. Operating at frequencies of 500 GHz-700 GHz, free-running linewidths around 10 MHz have been reported.…”

Section: A Heterodyne Oscillation Linewidthmentioning

confidence: 99%

Simulation and Measurement of HTS Josephson Heterodyne Oscillator

Macfarlane

Taylor³

et al. 2009

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

The Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. We have now modified the fabrication procedures, and adjusted the shunt resistors and bias current values so that higher frequencies can be achieved. The Josephson junctions are of step-edge type, rather than the bi-crystal type used in our earlier work. The step-edge technique permits much more flexibility in the geometrical lay-out and utilizes the more cost-effective single-crystal MgO substrates. In the present paper, we report numerical simulations and experimental measurements on these devices in the frequency range up to 2 GHz.

show abstract

“…In estimating S noise ͑0͒ we may use the relation between the magnetic field and bias current fluctuations. Recent measurements 40 of the linewidth in FFO indicate that fluctuating bias current ␦f͑t͒ in the control line generates magnetic field fluctuation ␦B͑t͒ in the LJJ. In reverse, magnetic field fluctuations due to both external and internal sources produce bias current fluctuations.…”

Section: Discussionmentioning

confidence: 99%

Decoherence in Josephson vortex quantum bits: Long-Josephson-junction approach to a two-state system

2006

View full text Add to dashboard Cite

We investigated decoherence of a Josephson vortex quantum bit ͑qubit͒ in dissipative and noisy environment. As the Josephson vortex qubit ͑JVQ͒ is fabricated by using a long Josephson junction ͑LJJ͒, we use the perturbed sine-Gordon equation to describe the phase dynamics representing a two-state system and estimate the effects of quasiparticle dissipation and weakly fluctuating critical and bias currents on the relaxation time T 1 and on the dephasing time T . We show that the critical current fluctuation does not contribute to dephasing of the qubit in the lowest order approximation. Modeling the weak current variation from magnetic field fluctuations in the LJJ by using the Gaussian colored noise with long correlation time, we show that the coherence time T 2 is limited by the low frequency current noise at very low temperatures. Also, we show that a ultra-long coherence time may be obtained from the JVQ by using experimentally accessible value of physical parameters.

show abstract

Externally phase-locked flux flow oscillator for submm integrated receivers: achievements and limitations

Cited by 11 publications

References 19 publications

Fluxon modes and phase-locking at 600 GHz in superconducting tunnel junction nonuniform arrays

Fluxon modes and phase-locking at 600 GHz in superconducting tunnel junction nonuniform arrays

Simulation and Measurement of HTS Josephson Heterodyne Oscillator

Decoherence in Josephson vortex quantum bits: Long-Josephson-junction approach to a two-state system

Contact Info

Product

Resources

About