Surface-resistance measurements using superconducting stripline resonators

Hafner, D.; Dressel, Martin; Scheffler, Marc

doi:10.1063/1.4856475

Cited by 33 publications

(72 citation statements)

References 71 publications

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“…At frequencies deviating from the resonance frequency the transmission decreases rapidly, leading to a Lorentzian form of the transmission signal around resonance frequencies [58]. After correction of the data performed similar to [38], a fit of a Lorentzian with center frequency ν and full width at half maximum ∆ν is possible. This enables the calculation of the quality factor Q = ν/∆ν for any given resonance, defined as the ratio of power stored to power dissipated each cycle.…”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

“…depend on the applied microwave power, due to two-level fluctuators [15] whereas at very high powers there can be nonlinear behavior due to the superconductor [57]. For our experiments, we want the applied power to be high enough for good signal-to-noise ratio in the transmission measurement but yet well below the power range where our stripline resonators becomes non-linear, [38], and we eventually used an input power of −30 dBm.…”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

“…The determination of the quality factor Q also allows for the calculation of the surface resistance [38] …”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

“…with Γ a geometrical constant of the resonator [38,59] and µ 0 the permeability constant. Additionally the surface reactance [1]…”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

“…Studying conducting materials is also our motivation for the development of superconducting Pb stripline resonators that can act as compact and sensitive probes in cryogenic microwave spectroscopy [36][37][38]. Here Pb with T c ≈ 7.2 K and a critical magnetic field of about B c ≈ 80 mT is a well suited basis material [39], as it can be processed for thin films rather easily.…”

Section: Introductionmentioning

confidence: 99%

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Superconducting Pb stripline resonators in parallel magnetic field and their application for microwave spectroscopy

Ebensperger¹,

Thiemann²,

Dressel³

et al. 2016

Supercond. Sci. Technol.

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Abstract. Planar superconducting microwave resonators are key elements in a variety of technical applications and also act as sensitive probes for microwave spectroscopy of various materials of interest in present solid state research. Here superconducting Pb is a suitable material as a basis for microwave stripline resonators.To utilize Pb stripline resonators in a variable magnetic field (e.g. in ESR measurements), the electrodynamics of such resonators in finite magnetic field has to be well understood. Therefore we performed microwave transmission measurements (with ample applied power to work in linear response) on superconducting Pb stripline resonators in a variable, parallel magnetic field. We determined surface resistance, penetration depth as well as real and imaginary parts, σ 1 and σ 2 , of the complex conductivity of superconducting Pb as a function of magnetic field. Here we find features reminiscent of those in temperaturedependent measurements, such as a maximum in σ 1 (coherence peak). At magnetic fields above the critical field of this type-I superconductor we still find a low-loss microwave response, which we assign to remaining superconductivity in the form of filaments within the Pb. Hysteresis effects are found in the quality factor of resonances once the swept magnetic field has exceeded the critical magnetic field. This is due to normal conducting areas that are pinned and can therefore persist in the superconducting phase. Besides zero-field-cooling we show an alternative way to eliminate these even at T < Tc. Based on our microwave data, we also determine the critical magnetic field and the critical temperature of Pb in a temperature range between 1.6K and 6.5K and magnetic fields up to 140mT, showing good agreement with BCS predictions. We furthermore study a Sn sample in a Pb resonator to demonstrate the applicability of superconducting Pb stripline resonators in the experimental study of other (super-)conducting materials in a variable magnetic field.

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Section: Experimental Setup and Methodsmentioning

confidence: 99%

Section: Experimental Setup and Methodsmentioning

confidence: 99%

“…The determination of the quality factor Q also allows for the calculation of the surface resistance [38] …”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

“…with Γ a geometrical constant of the resonator [38,59] and µ 0 the permeability constant. Additionally the surface reactance [1]…”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Superconducting Pb stripline resonators in parallel magnetic field and their application for microwave spectroscopy

Ebensperger¹,

Thiemann²,

Dressel³

et al. 2016

Supercond. Sci. Technol.

Self Cite

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Signatures of Phase Transitions in the Microwave Response of YbRh2Si2

et al. 2015

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We used a spectroscopic microwave technique utilizing superconducting stripline resonators at frequencies between 3 GHz and 15 GHz to examine the charge dynamics of YbRh2Si2 at temperatures and magnetic fields close to the quantum critical point. The different electronic phases of this heavy-fermion compound, in particular the antiferromagnetic, Fermi-liquid, and non-Fermi-liquid regimes, were probed with temperature-dependent microwave measurements between 40 mK and 600 mK at a set of different magnetic fields up to 140 mT. Signatures of phase transitions were observed, which give information about the dynamic response of this peculiar material that exhibits field-tuned quantum criticality and pronounced deviations from Fermi-liquid theory.

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