Rapid single flux quantum logic in high temperature superconductor technology

K. Shunmugavel

Research output: ThesisPhD Thesis - Research UT, graduation UT

Abstract

A Josephson junction is the basic element of rapid single flux quantum logic (RSFQ) circuits. A high operating speed and low power consumption are the main advantages of RSFQ logic over semiconductor electronic circuits. To realize complex RSFQ circuits in HTS technology one needs a reproducible fabrication of Josephson junctions with low parameter spread. High quality HTS junctions require a fully epitaxial multilayer structure with clean interfaces and a smooth surface morphology. Neodymium barium copper oxide (NBCO) thin films were used as superconducting electrodes due to their high transition temperature and low surface roughness. NBCO forms a solid solution in which Nd3+ ions can substitute for Ba2+ ions with the formula Nd1+xBa2-xCu3Oy (x=0.12 in our study). Cation disorder and oxygen deficiency affect the structural and electronic properties of grown NBCO films. Target composition, substrate temperature, oxygen partial-pressure and annealing steps are properly chosen to obtain smooth films with a high transition temperature. NBCO is deposited on an STO buffered MgO substrate at a pressure of 0.35 mbar in an Argon and Oxygen (20:1) gas mixture. The substrate temperature was fixed at 8200 C. The deposited film is smooth with a surface roughness of 1-3 nm for a 150 nm thick layer and a transition temperature around 90K.
LanguageUndefined
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • Supervisor
  • Brinkman, Alexander , Supervisor
Award date13 Oct 2006
Place of PublicationEnschede
Print ISBNs9789036524292
StatePublished - 13 Oct 2006

Keywords

  • IR-57620

Cite this

@phdthesis{1e4c2266533040f88069bb5c6a5a1119,
title = "Rapid single flux quantum logic in high temperature superconductor technology",
abstract = "A Josephson junction is the basic element of rapid single flux quantum logic (RSFQ) circuits. A high operating speed and low power consumption are the main advantages of RSFQ logic over semiconductor electronic circuits. To realize complex RSFQ circuits in HTS technology one needs a reproducible fabrication of Josephson junctions with low parameter spread. High quality HTS junctions require a fully epitaxial multilayer structure with clean interfaces and a smooth surface morphology. Neodymium barium copper oxide (NBCO) thin films were used as superconducting electrodes due to their high transition temperature and low surface roughness. NBCO forms a solid solution in which Nd3+ ions can substitute for Ba2+ ions with the formula Nd1+xBa2-xCu3Oy (x=0.12 in our study). Cation disorder and oxygen deficiency affect the structural and electronic properties of grown NBCO films. Target composition, substrate temperature, oxygen partial-pressure and annealing steps are properly chosen to obtain smooth films with a high transition temperature. NBCO is deposited on an STO buffered MgO substrate at a pressure of 0.35 mbar in an Argon and Oxygen (20:1) gas mixture. The substrate temperature was fixed at 8200 C. The deposited film is smooth with a surface roughness of 1-3 nm for a 150 nm thick layer and a transition temperature around 90K.",
keywords = "IR-57620",
author = "K. Shunmugavel",
year = "2006",
month = "10",
day = "13",
language = "Undefined",
isbn = "9789036524292",
school = "University of Twente",

}

Shunmugavel, K 2006, 'Rapid single flux quantum logic in high temperature superconductor technology', University of Twente, Enschede.

Rapid single flux quantum logic in high temperature superconductor technology. / Shunmugavel, K.

Enschede, 2006. 99 p.

Research output: ThesisPhD Thesis - Research UT, graduation UT

TY - THES

T1 - Rapid single flux quantum logic in high temperature superconductor technology

AU - Shunmugavel,K.

PY - 2006/10/13

Y1 - 2006/10/13

N2 - A Josephson junction is the basic element of rapid single flux quantum logic (RSFQ) circuits. A high operating speed and low power consumption are the main advantages of RSFQ logic over semiconductor electronic circuits. To realize complex RSFQ circuits in HTS technology one needs a reproducible fabrication of Josephson junctions with low parameter spread. High quality HTS junctions require a fully epitaxial multilayer structure with clean interfaces and a smooth surface morphology. Neodymium barium copper oxide (NBCO) thin films were used as superconducting electrodes due to their high transition temperature and low surface roughness. NBCO forms a solid solution in which Nd3+ ions can substitute for Ba2+ ions with the formula Nd1+xBa2-xCu3Oy (x=0.12 in our study). Cation disorder and oxygen deficiency affect the structural and electronic properties of grown NBCO films. Target composition, substrate temperature, oxygen partial-pressure and annealing steps are properly chosen to obtain smooth films with a high transition temperature. NBCO is deposited on an STO buffered MgO substrate at a pressure of 0.35 mbar in an Argon and Oxygen (20:1) gas mixture. The substrate temperature was fixed at 8200 C. The deposited film is smooth with a surface roughness of 1-3 nm for a 150 nm thick layer and a transition temperature around 90K.

AB - A Josephson junction is the basic element of rapid single flux quantum logic (RSFQ) circuits. A high operating speed and low power consumption are the main advantages of RSFQ logic over semiconductor electronic circuits. To realize complex RSFQ circuits in HTS technology one needs a reproducible fabrication of Josephson junctions with low parameter spread. High quality HTS junctions require a fully epitaxial multilayer structure with clean interfaces and a smooth surface morphology. Neodymium barium copper oxide (NBCO) thin films were used as superconducting electrodes due to their high transition temperature and low surface roughness. NBCO forms a solid solution in which Nd3+ ions can substitute for Ba2+ ions with the formula Nd1+xBa2-xCu3Oy (x=0.12 in our study). Cation disorder and oxygen deficiency affect the structural and electronic properties of grown NBCO films. Target composition, substrate temperature, oxygen partial-pressure and annealing steps are properly chosen to obtain smooth films with a high transition temperature. NBCO is deposited on an STO buffered MgO substrate at a pressure of 0.35 mbar in an Argon and Oxygen (20:1) gas mixture. The substrate temperature was fixed at 8200 C. The deposited film is smooth with a surface roughness of 1-3 nm for a 150 nm thick layer and a transition temperature around 90K.

KW - IR-57620

M3 - PhD Thesis - Research UT, graduation UT

SN - 9789036524292

CY - Enschede

ER -