Leakage current of a superconductor: Normal metal tunnel junction connected to a high-temperature environment

A. di Marco, V.F. Maisi, J.P. Pekola, F.W.J. Hekking

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)

Abstract

We consider a voltage-biased normal metal-insulator-superconductor (NIS) tunnel junction, model system features the commonly observed subgap leakage current in NIS junctions through photon-assisted tunneling which is detrimental for applications. We first consider a NIS junction directly coupled to the environment and analyze the subgap leakage current both analytically and numerically; we discuss the link with the phenomenological Dynes parameter. Then, we focus on a circuit where a low-temperature lossy transmission line is inserted between the NIS junction and the environment. We show that the amplitude of the transmitted frequencies relevant for the photon-assisted tunneling is exponentially suppressed as the length l and the resistance per unit length R0 of the line are increased. Consequently, the subgap current is reduced exponentially as well. This property can not be obtained by means of lumped circuit elements. We finally discuss our results in view of the performance of NIS junctions in applications.
Original languageEnglish
Article number174507
JournalPhysical Review B: Condensed Matter and Materials Physics
Volume88
Issue number17
DOIs
Publication statusPublished - 2013
MoE publication typeA1 Journal article-refereed

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Tunnel junctions
Leakage currents
Superconducting materials
Metals
Photons
Temperature
Networks (circuits)
Electric lines
Electric potential

Keywords

  • superconductors

Cite this

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title = "Leakage current of a superconductor: Normal metal tunnel junction connected to a high-temperature environment",
abstract = "We consider a voltage-biased normal metal-insulator-superconductor (NIS) tunnel junction, model system features the commonly observed subgap leakage current in NIS junctions through photon-assisted tunneling which is detrimental for applications. We first consider a NIS junction directly coupled to the environment and analyze the subgap leakage current both analytically and numerically; we discuss the link with the phenomenological Dynes parameter. Then, we focus on a circuit where a low-temperature lossy transmission line is inserted between the NIS junction and the environment. We show that the amplitude of the transmitted frequencies relevant for the photon-assisted tunneling is exponentially suppressed as the length l and the resistance per unit length R0 of the line are increased. Consequently, the subgap current is reduced exponentially as well. This property can not be obtained by means of lumped circuit elements. We finally discuss our results in view of the performance of NIS junctions in applications.",
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language = "English",
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Leakage current of a superconductor : Normal metal tunnel junction connected to a high-temperature environment. / di Marco, A.; Maisi, V.F.; Pekola, J.P.; Hekking, F.W.J.

In: Physical Review B: Condensed Matter and Materials Physics, Vol. 88, No. 17, 174507, 2013.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Leakage current of a superconductor

T2 - Normal metal tunnel junction connected to a high-temperature environment

AU - di Marco, A.

AU - Maisi, V.F.

AU - Pekola, J.P.

AU - Hekking, F.W.J.

PY - 2013

Y1 - 2013

N2 - We consider a voltage-biased normal metal-insulator-superconductor (NIS) tunnel junction, model system features the commonly observed subgap leakage current in NIS junctions through photon-assisted tunneling which is detrimental for applications. We first consider a NIS junction directly coupled to the environment and analyze the subgap leakage current both analytically and numerically; we discuss the link with the phenomenological Dynes parameter. Then, we focus on a circuit where a low-temperature lossy transmission line is inserted between the NIS junction and the environment. We show that the amplitude of the transmitted frequencies relevant for the photon-assisted tunneling is exponentially suppressed as the length l and the resistance per unit length R0 of the line are increased. Consequently, the subgap current is reduced exponentially as well. This property can not be obtained by means of lumped circuit elements. We finally discuss our results in view of the performance of NIS junctions in applications.

AB - We consider a voltage-biased normal metal-insulator-superconductor (NIS) tunnel junction, model system features the commonly observed subgap leakage current in NIS junctions through photon-assisted tunneling which is detrimental for applications. We first consider a NIS junction directly coupled to the environment and analyze the subgap leakage current both analytically and numerically; we discuss the link with the phenomenological Dynes parameter. Then, we focus on a circuit where a low-temperature lossy transmission line is inserted between the NIS junction and the environment. We show that the amplitude of the transmitted frequencies relevant for the photon-assisted tunneling is exponentially suppressed as the length l and the resistance per unit length R0 of the line are increased. Consequently, the subgap current is reduced exponentially as well. This property can not be obtained by means of lumped circuit elements. We finally discuss our results in view of the performance of NIS junctions in applications.

KW - superconductors

U2 - 10.1103/PhysRevB.88.174507

DO - 10.1103/PhysRevB.88.174507

M3 - Article

VL - 88

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

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