Improved excitation mode selectivity of high-Tc superconducting terahertz emitters

Kashiwagi, Takanari; Yuasa, Takumi; Tanabe, Yasuhiro; Imai, Takeshi; Kuwano, Genki; Ota, Rikuo; Nakamura, Kento; Ono, Yukino; Kaneko, Yasunari; Tsujimoto, Manabu; Minami, Hidetoshi; Yamamoto, Takashi; Klemm, Richard A.; Kadowaki, K.

doi:10.1063/1.5033914

Cited by 24 publications

(21 citation statements)

References 90 publications

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“…We have already studied the radiation characteristics of various types of SAMs by using the square shape rigs shown in Figure 2 a [ 43 , 52 ] and the cylindrical shape rigs displayed in Figure 2 b [ 65 ] and confirmed that almost similar electric and cooling properties can be obtained. These rigs enable us to make easy electrical contact to the SAMs as well as to obtain high heat exhausting characteristics from the SAMs.…”

Section: Methodsmentioning

confidence: 80%

“…The SAMs were sandwiched by two metallic film coated sapphire substrates in order to make good electrical and thermal contacts. These rigs were fixed by four screws, then, a hemispherical-shaped Si lens with a diameter of 4 mm was attached to the top of the front sapphire substrate [ 43 , 52 , 65 ]. The electromagnetic waves from the SAMs were collected by the lens.…”

Section: Methodsmentioning

confidence: 99%

“…The experimental results obtained from local temperature measurement techniques for mesa structures of Bi2212 crystals revealed the very inhomogeneous local temperature distributions

of the mesas, often called a hot-spot when the local temperature

exceeds the superconducting transition temperature

[ 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ]. Several device structures have been proposed to overcome the heating effect [ 30 , 31 , 41 , 43 , 65 ]. Due to these improvements in the design of Bi2212-THz emitters by adding heat exhausting structures, the device characteristics such as the radiation intensities, frequencies [ 30 , 31 , 43 ], and the device working bath temperatures [ 38 , 66 , 67 ] have also improved.…”

Section: Introductionmentioning

confidence: 99%

“…In order to further develop the device characteristics of Bi2212-THz emitters, improvements in the fabrication techniques and processes of the mesa devices are required. We developed a device structure by using a stand alone type of mesa structures (abbreviated as SAMs) to reduce Joule heating of mesa structures and reported the improved radiation characteristics [ 30 , 41 , 43 , 52 , 65 ].…”

Section: Introductionmentioning

confidence: 99%

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Study of Radiation Characteristics of Intrinsic Josephson Junction Terahertz Emitters with Different Thickness of Bi2Sr2CaCu2O8+δ Crystals

et al. 2021

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The radiation intensity from the intrinsic Josephson junction high-Tc superconductor Bi2Sr2CaCu2O8+δ terahertz emitters (Bi2212-THz emitters) is one of the most important characteristics for application uses of the device. In principle, it would be expected to be improved with increasing the number of intrinsic Josephson junctions N in the emitters. In order to further improve the device characteristics, we have developed a stand alone type of mesa structures (SAMs) of Bi2212 crystals. Here, we understood the radiation characteristics of our SAMs more deeply, after we studied the radiation characteristics from three SAMs (S1, S2, and S3) with different thicknesses. Comparing radiation characteristics of the SAMs in which the number of intrinsic Josephson junctions are N∼ 1300 (S1), 2300 (S2), and 3100 (S3), respectively, the radiation intensity, frequency as well as the characteristics of the device working bath temperature are well understood. The strongest radiation of the order of few tens of microwatt was observed from the thickest SAM of S3. We discussed this feature through the N2-relationship and the radiation efficiency of a patch antenna. The thinner SAM of S1 can generate higher radiation frequencies than the thicker one of S3 due to the difference of the applied voltage per junctions limited by the heat-removal performance of the device structures. The observed features in this study are worthwhile designing Bi2212-THz emitters with better emission characteristics for many applications.

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Section: Methodsmentioning

confidence: 80%

Section: Methodsmentioning

confidence: 99%

“…The experimental results obtained from local temperature measurement techniques for mesa structures of Bi2212 crystals revealed the very inhomogeneous local temperature distributions

of the mesas, often called a hot-spot when the local temperature

exceeds the superconducting transition temperature

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Study of Radiation Characteristics of Intrinsic Josephson Junction Terahertz Emitters with Different Thickness of Bi2Sr2CaCu2O8+δ Crystals

et al. 2021

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“…Layered high-temperature superconductor Bi 2 Sr 2 CaCu 2 O 8+ (Bi-2212) may provide an alternative technology for creation of cryogenic THz sources [9][10][11][12][13][14][15][16][17][18][19][20][21]. Bi-2212 represents a natural stack of atomic scale intrinsic Josephson junctions (ĲJ's) [22][23][24][25].…”

Section: Introductionmentioning

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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On-Chip Sensing of Hotspots in Superconducting Terahertz Emitters

et al. 2020

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Intrinsic Josephson junctions in high-temperature superconductor Bi2Sr2CaCu2O8+δ (BSCCO) are known for their capability to emit high-power terahertz photons with widely tunable frequencies. Hotspots, as inhomogeneous temperature distributions across the junctions, are believed to play a critical role in synchronizing the gauge-invariant phase difference among the junctions, so as to achieve coherent strong emission. In this paper, we demonstrate an on-chip in situ sensing technique that can characterize hotspot distributions on BSCCO. This is achieved by fabricating a series of micro-nanosized “sensor” junctions on top of an “emitter” junction and measuring the critical current on the sensors versus the bias current applied to the emitter. This fully electronic on-chip design can enable efficient close-loop control of hotspots in BSCCO junctions and significantly enhance the functionality of superconducting terahertz emitters.

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Improved excitation mode selectivity of high-Tc superconducting terahertz emitters

Abstract: Articles you may be interested in Circularly polarized terahertz radiation monolithically generated by cylindrical mesas of intrinsic Josephson junctions

Cited by 24 publications

References 90 publications

Study of Radiation Characteristics of Intrinsic Josephson Junction Terahertz Emitters with Different Thickness of Bi2Sr2CaCu2O8+δ Crystals

Study of Radiation Characteristics of Intrinsic Josephson Junction Terahertz Emitters with Different Thickness of Bi2Sr2CaCu2O8+δ Crystals

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

On-Chip Sensing of Hotspots in Superconducting Terahertz Emitters

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Improved excitation mode selectivity of high-Tc superconducting terahertz emitters

Abstract: Articles you may be interested in Circularly polarized terahertz radiation monolithically generated by cylindrical mesas of intrinsic Josephson junctions

Cited by 24 publications

References 90 publications

Study of Radiation Characteristics of Intrinsic Josephson Junction Terahertz Emitters with Different Thickness of Bi2Sr2CaCu2O8+δ Crystals

Study of Radiation Characteristics of Intrinsic Josephson Junction Terahertz Emitters with Different Thickness of Bi2Sr2CaCu2O8+δ Crystals

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

On-Chip Sensing of Hotspots in Superconducting Terahertz Emitters

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Product

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