Synchronization of Large Josephson-Junction Arrays by Traveling Electromagnetic Waves

Galin, M. A.; Borodianskyi, Evgenii A.; Kurin, V. V.; Shereshevskiy, I. A.; Vdovicheva, N. K.; Krasnov, Vladimir M.; Клушин, А.М.

doi:10.1103/physrevapplied.9.054032

Cited by 33 publications

(43 citation statements)

References 25 publications

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“…The tolerable dissipation power can be significantly enhanced by spreading it between several smaller emitters [10,19] because smaller mesa structures are less prone to self-heating [14,28,29,31]. Such a strategy has been successfully proved for arrays of Josephson junctions [48][49][50], for which coherent emission from up to 9000 synchronized junctions was reported [49]. Yet, the ultimate dissipation power is limited by the cooling power of the cryostat itself.…”

Section: Discussionmentioning

confidence: 99%

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Krasnov¹,

Novikova²,

Cattaneo³

et al. 2021

Beilstein J. Nanotechnol.

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Impedance matching and heat management are important factors influencing the performance of terahertz sources. In this work we analyze thermal and radiative properties of such devices based on mesa structures of a layered high-temperature superconductor Bi2Sr2CaCu2O8+δ. Two types of devices are considered containing either a conventional large single crystal or a whisker. We perform numerical simulations for various geometrical configurations and parameters and make a comparison with experimental data for the two types of devices. It is demonstrated that the structure and the geometry of both the superconductor and the electrodes play important roles. In crystal-based devices an overlap between the crystal and the electrode leads to appearance of a large parasitic capacitance, which shunts terahertz emission and prevents impedance matching with open space. The overlap is avoided in whisker-based devices. Furthermore, the whisker and the electrodes form a turnstile (crossed-dipole) antenna facilitating good impedance matching. This leads to more than an order of magnitude enhancement of the radiation power efficiency in whisker-based, compared to crystal-based, devices. These results are in good agreement with presented experimental data.

show abstract

Section: Discussionmentioning

confidence: 99%

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Krasnov¹,

Novikova²,

Cattaneo³

et al. 2021

Beilstein J. Nanotechnol.

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show abstract

“…The tolerable dissipation power can be significantly enhanced by spreading it between several smaller emitters [10,19] because smaller mesa structures are less prone to self-heating [14,27,28,30]. Such a strategy has been successfully proved for arrays of Josephson junctions [45][46][47], for which coherent emission from up to 9000 synchronized junctions was reported [46]. Yet, the ultimate dissipation power is limited by the cooling power of the cryostat itself.…”

Section: Discussionmentioning

confidence: 99%

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Krasnov¹,

Novikova²,

Cattaneo³

et al. 2021

Preprint

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Impedance matching and heat management are important factors influencing performance of THz sources. In this work we analyze thermal and radiative properties of such devices based on mesa structures of a layered high-temperature superconductor Bi2Sr2CaCu2O8+δ. Two types of devices are considered, containing either a conventional large single crystal, or a whisker. We perform numerical simulations for various geometrical configurations and parameters and make a comparison with experimental data for the two types of devices. It is demonstrated that the structure and the geometry of both the superconductor and the electrodes are playing important roles. In crystal-based devices an overlap between the crystal and the electrode leads to appearance of a large parasitic capacitance, which shunts THz emission and prevents impedance matching with open space. The overlap is avoided in whisker-based devices. Furthermore, the whisker and the electrodes form a turnstile (crossed-dipole) antenna facilitating good impedance matching. This leads to more than an order of magnitude enhancement of the radiation power efficiency in whisker-based, compared to crystal-based devices. These results are in good agreement with presented experimental data.

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“…Synchronization is also one of the most frequent phenomena in both nature and technology. Examples of synchronized networks include hippocampal and cortical neuronal activities [160,161], fireflies [162], pacemaker cells in the heart [163], arrays of lasers and power generators [164], arrays of micromechanical oscillators [165], superconducting Josephson junction arrays [166,167], and synchronization in spin transfer torque oscillators [8,9,35,168]. However, implementing a large physical network that meets the technical requirements-such as room-temperature operation, scaling, integration, high speed, and low power consumption-has remained a challenge.…”

Section: Two-dimensional Spin Hall Nano-oscillator Arraysmentioning

confidence: 99%

Current Modulation of Nanoconstriction Spin-Hall Nano-Oscillators

et al. 2017

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This thesis explores the vibrant phenomena of spin Hall nano-oscillators (SHNOs); from wideband oscillation at the GHz range, through propagating spin-wave emission, to mutual synchronization in two-dimensional SHNO arrays, and tries to lay the foundation for a far-reaching SHNO technology, targeting magnonics, microwave signal generation, and neuromorphic computing. After a short introduction to the theoretical background in Chapter 1, in Chapter 2, ways of improving the spin transport properties between NiFe and Pt are explored: an 0.4 nm ultra-thin layer of Hf at the NiFe/Pt interface is found to reduce the threshold current by 20% as a result of the change in spin mixing conductance G Ö eff. Then, W/CoFeB/MgO stacks with perpendicular magnetic anisotropy (PMA) are used to demonstrate wide frequency tunability and sub-mA threshold currents in CMOS compatible SHNOs. By further increasing the PMA, the auto-oscillation frequency exceeds the ferromagnetic resonance (FMR) frequency, turning the SHNO into a propagating spin-wave emitter in which the propagation wave-vector is tunable with applied current and field. Finally, a GHz nano-scale SHNO modulated by an 80 MHz radio-frequency (RF) current is presented. The modulation needs no bulky microwave mixer, promising a compact modulator unit. Chapter 3 introduces two-dimensional SHNO arrays. Robust mutual synchronization is demonstrated in arrays accommodating up to 64 oscillators, achieving record high quality factors of 170,000 at an operating frequency of 10 GHz. Injection of two external microwave signals reproduces the two-dimensional synchronization maps used in neuromorphic vowel recognition. Chapter 4 emphasizes the importance of individual SHNO control in arrays. Gated SHNOs are demonstrated with substantial voltage tuning of the threshold current and the SHNO frequency. Voltage controlled mutual synchronization is also demonstrated. The MgO/AlO x /Si 3 N 4 gate is found to exhibit a memristive behavior governed by ion migration and acts as an embedded memory making each SHNO a complete non-volatile oscillator with integrated weights. The exciting nature of coupled non-volatile oscillator arrays controlled by electric field could lead to a paradigm shift in non-conventional computing. Chapter 5 discusses the implications of the demonstrated SHNO technology and how it may impact future applications.

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Synchronization of Large Josephson-Junction Arrays by Traveling Electromagnetic Waves

Cited by 33 publications

References 25 publications

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Current Modulation of Nanoconstriction Spin-Hall Nano-Oscillators

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Synchronization of Large Josephson-Junction Arrays by Traveling Electromagnetic Waves

Cited by 33 publications

References 25 publications

Design aspects of Bi2Sr2CaCu2O8+δ THz sources: optimization of thermal and radiative properties

Design aspects of Bi2Sr2CaCu2O8+δ THz sources: optimization of thermal and radiative properties

Design aspects of Bi2Sr2CaCu2O8+δ THz sources: optimization of thermal and radiative properties

Current Modulation of Nanoconstriction Spin-Hall Nano-Oscillators

Contact Info

Product

Resources

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Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties