Terahertz electrodynamics and superconducting energy gap of NbN

Kyung Ik Sim; Young Chan Jo; Taewoo Ha; Jong Hyeon Kim; Jae Hoon Kim; Hirotake Yamamori

doi:10.3938/jkps.71.571

Terahertz electrodynamics and superconducting energy gap of NbN

Kyung Ik Sim, Young Chan Jo, Taewoo Ha, Jong Hyeon Kim, Jae Hoon Kim, Hirotake Yamamori

Department of Physics

Research output: Contribution to journal › Article › peer-review

4 Citations (Scopus)

Abstract

We have measured the transmission spectra of the conventional Bardeen-Cooper-Schrieffer (BCS) superconductor niobium nitride (NbN) thin films (T_c = 11 K) using terahertz time-domain spectroscopy (THz-TDS) over the spectral range of 10 - 110 cm ⁻¹ and the temperature range of 3.9 - 295 K. We extracted both the real part, σ₁, and the imaginary part, σ₂, of the optical conductivity, σ̃ = σ₁ + iσ₂, independently and simultaneously, without a Kramers-Kronig analysis. The superconducting gap Δ(T) was observed in the real part of the conductivity, σ₁, below T_c = 11 K with a maximum value of 2Δ(0) = 30 cm ⁻¹ and the gap ratio 2Δ(0)/k_BT_c = 3.92.

Original language	English
Pages (from-to)	571-574
Number of pages	4
Journal	Journal of the Korean Physical Society
Volume	71
Issue number	9
DOIs	https://doi.org/10.3938/jkps.71.571
Publication status	Published - 2017 Nov 1

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Publisher Copyright:
© 2017, The Korean Physical Society.

All Science Journal Classification (ASJC) codes

Physics and Astronomy(all)

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10.3938/jkps.71.571

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title = "Terahertz electrodynamics and superconducting energy gap of NbN",

abstract = "We have measured the transmission spectra of the conventional Bardeen-Cooper-Schrieffer (BCS) superconductor niobium nitride (NbN) thin films (Tc = 11 K) using terahertz time-domain spectroscopy (THz-TDS) over the spectral range of 10 - 110 cm −1 and the temperature range of 3.9 - 295 K. We extracted both the real part, σ1, and the imaginary part, σ2, of the optical conductivity, {\~σ} = σ1 + iσ2, independently and simultaneously, without a Kramers-Kronig analysis. The superconducting gap Δ(T) was observed in the real part of the conductivity, σ1, below Tc = 11 K with a maximum value of 2Δ(0) = 30 cm −1 and the gap ratio 2Δ(0)/kBTc = 3.92.",

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AU - Sim, Kyung Ik

AU - Jo, Young Chan

AU - Ha, Taewoo

AU - Kim, Jong Hyeon

AU - Kim, Jae Hoon

AU - Yamamori, Hirotake

PY - 2017/11/1

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N2 - We have measured the transmission spectra of the conventional Bardeen-Cooper-Schrieffer (BCS) superconductor niobium nitride (NbN) thin films (Tc = 11 K) using terahertz time-domain spectroscopy (THz-TDS) over the spectral range of 10 - 110 cm −1 and the temperature range of 3.9 - 295 K. We extracted both the real part, σ1, and the imaginary part, σ2, of the optical conductivity, σ̃ = σ1 + iσ2, independently and simultaneously, without a Kramers-Kronig analysis. The superconducting gap Δ(T) was observed in the real part of the conductivity, σ1, below Tc = 11 K with a maximum value of 2Δ(0) = 30 cm −1 and the gap ratio 2Δ(0)/kBTc = 3.92.

AB - We have measured the transmission spectra of the conventional Bardeen-Cooper-Schrieffer (BCS) superconductor niobium nitride (NbN) thin films (Tc = 11 K) using terahertz time-domain spectroscopy (THz-TDS) over the spectral range of 10 - 110 cm −1 and the temperature range of 3.9 - 295 K. We extracted both the real part, σ1, and the imaginary part, σ2, of the optical conductivity, σ̃ = σ1 + iσ2, independently and simultaneously, without a Kramers-Kronig analysis. The superconducting gap Δ(T) was observed in the real part of the conductivity, σ1, below Tc = 11 K with a maximum value of 2Δ(0) = 30 cm −1 and the gap ratio 2Δ(0)/kBTc = 3.92.

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Terahertz electrodynamics and superconducting energy gap of NbN

Abstract

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