We describe the fabrication of high performance YBa2Cu3O7-δ （YBCO） radio frequency （RF） superconducting quantum interference devices （SQUIDs）, which were prepared on 5 mm×5 mm LaAlO3 （LAO） substrates by ...We describe the fabrication of high performance YBa2Cu3O7-δ （YBCO） radio frequency （RF） superconducting quantum interference devices （SQUIDs）, which were prepared on 5 mm×5 mm LaAlO3 （LAO） substrates by employing stepedge junctions （SEJs） and in flip-chip configuration with 12 mm×12 mm resonators. The step in the substrate was produced by Ar ion etching with step angles ranging from 47° to 61°, which is steep enough to ensure the formation of grain boundaries （GBs） at the step edges. The YBCO film was deposited using the pulsed laser deposition （PLD） technique with a film thickness half of the height of the substrate step. The inductance of the SQUID washer was designed to be about 157 pH. Under these circumstances, high performance YBCO RF SQUIDs were successfully fabricated with a typical flux-voltage transfer ratio of 83 mV/φ0, a white flux noise of 29 μφ0/√Hz, and the magnetic field sensitivity as high as 80 fT/√Hz. These devices have been applied in magnetocardiography and geological surveys.展开更多
We propose a scheme to generate a three-qubit three-IeveI singlet state in cavity QED, by placing three A-type SQUIDs in a single mode cavity. In this scheme, we make use of the interaction between the SQUIDs and cavi...We propose a scheme to generate a three-qubit three-IeveI singlet state in cavity QED, by placing three A-type SQUIDs in a single mode cavity. In this scheme, we make use of the interaction between the SQUIDs and cavity filed, and the classical pulses. The cavity fields are in vacuum state during the whole operation processes of creating the entanglement, and there is no quantum information transformation between the SQUIDs and cavity fields. Because of the advantage of the SQUID-cavity system, the quality factor of the cavity is greatly relaxed.展开更多
We have developed a simple sintering system to prepare the yttria-stabilized-zirconia(YSZ)bicrystals.Grain-boundary junctions made from the epitaxial YBa_(2)Cu_(3)O_(7-δ) films on the bicrystal substrates demonstrate...We have developed a simple sintering system to prepare the yttria-stabilized-zirconia(YSZ)bicrystals.Grain-boundary junctions made from the epitaxial YBa_(2)Cu_(3)O_(7-δ) films on the bicrystal substrates demonstrated Josephson behavior.Using new square washer design,single-level magnetometer of dc superconducting quantum interference.device(SQUID)has been fabricated.Owing to the flux focusing effect of the large washer,the magnetic field sensitivity of the devices has been enhanced.The magnetic field resolution of the magnetometer is IpT/Hz^(1/2) at 10Hz,and increases to 3pT/Hz^(1/2) at 1Hz at 77K.展开更多
Bicvystal Josephson junctions and direct current superconducting quantum inter ference devices(dc sQUIDs)were prepared on YBa_(2)Cu_(3)O_(7)(YBCO)thin films deposited on yttrium stabilized ZrO_(2) bicrystal substrates...Bicvystal Josephson junctions and direct current superconducting quantum inter ference devices(dc sQUIDs)were prepared on YBa_(2)Cu_(3)O_(7)(YBCO)thin films deposited on yttrium stabilized ZrO_(2) bicrystal substrates.The critical current densities J_(c)~2×10^(6)/cm^(2) for YBCO thin filmand(1-3)×10^(3)A/cm^(2) at boundaries were obtained at 77 K.For YBCO Josephson junctionmade on 28° misorientated boundary,the Shapiro steps were observed.The dc SQUID was madeon the 32° misorientated boundary junctions,which consisted of 40×40 m of loop and 2000×2000 pn planar superconductive flu.r focuser.The zoltage modulation depth of this SQUID was6 p.V,and the magnetic field sensitivity was estimated to be~2 pT/√Hz from the measurednoise level.展开更多
Double-microbridge de superconducting quantum interference devices(SQUIDs)have been fabricated from the postannealed Y_(1)Ba_(2)Cu_(3)O_(y) and Tl_(2)-Ba_(2)Ca_(2)Cu_(3)O_(y) thin films by chemical etching and ion mil...Double-microbridge de superconducting quantum interference devices(SQUIDs)have been fabricated from the postannealed Y_(1)Ba_(2)Cu_(3)O_(y) and Tl_(2)-Ba_(2)Ca_(2)Cu_(3)O_(y) thin films by chemical etching and ion milling patterning technique.The applied magnetic field dependences of the voltage of the YBCO and TBCCO SQUIDs have been studied at temperature ranging from 4.2 to 23K and at 77K.The largest output voltage of the devices were 3.4μV/Φ_(0 )(at 5K)for YBCO and 60μV/Φ_(0)(at 77K)for TBCCO.The properties of the output of these devices have been discussed.展开更多
The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with...The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with identical junctions and the series SQUIDs with different junctions were successfully fabricated. The Nb/Al-AlOx/Nb trilayer and input Nb coils were prepared by asputtering equipment. The SQUID devices were prepared by a sputtering and the lift-off method.Investigations by AFM, OM and SEM revealed the morphology and roughness of the Nb films and Nb/Al-AlOx/Nb trilayer.In addition, the current–voltage characteristics of the SQUID devices with identical junction and different junction areas were measured at 2.5 K in the He^3 refrigerator. The results show that the SQUID modulation depth is obviously affected by the junction area. The modulation depth obviously increases with the increase of the junction area in a certain range. It is found that the series SQUID with identical junction area has a transimpedance gain of 58 Ω approximately.展开更多
Objective:To analyze the safety and effectiveness of the ethylene-vinyl alcohol copolymer(EVOH)liquid embolic agent Squid(Emboflu,Switzerland)for the treatment of brain arteriovenous malformations.Materials and proced...Objective:To analyze the safety and effectiveness of the ethylene-vinyl alcohol copolymer(EVOH)liquid embolic agent Squid(Emboflu,Switzerland)for the treatment of brain arteriovenous malformations.Materials and procedures:Between April 2015 and July 2017,46 embolization treatments for brain arteriovenous malformations(BAVM)were performed in 25 patients using two Squid formulations(18 and 12).Six female and 19 male patients with a mean age of 34 years(range,9–62 years)were included.A total of 46 procedures were performed.The BAVMs were classified as Spetzler-Martin gradeⅡin 4 procedures,Ⅲin 27 procedures,and 1V in 15 procedures.Among the 25 patients,15 presented with hemorrhage,5 with seizures,and 5 with headache and neurology.The BAVMs were located in the temporal lobe in 5 patients,parietal lobe in 7 patients,frontal lobe in 3 patients,posterior fossa in 6 patients,basal ganglia in 3 patients,and parasagittal lobe in 1 patient.Results:The obliteration rate of the BAVMs ranged from 10%to 100%,with a mean of 33%.Most patients underwent their first or second embolization procedure.Four patients(8%)developed intracranial bleeding post procedure,with one death(2%).One patient(2%)experienced a seizure during the procedure;however,no intracranial bleeding was observed.Seven patients(15%)experienced perforations during catheter manipulation.One case(2%)of fractured catheter was recorded,but no significant complications were observed.The average volume of copolymer injected was 0.6 ml per nidus.Thirteen procedures used the Squid-12 formulation,29 procedures used the Squid-18 formulation,and 3 procedures used a combination of Squid-12 and-18 formulations.Conclusion:Squid is a safe and effective embolic agent for treating BAVMs.展开更多
Superconducting quantum interference devices(SQUIDs) are low-noise amplifiers that are essential for the readouts of translation edge sensors(TESs). The linear flux range is an important parameter for SQUID amplifiers...Superconducting quantum interference devices(SQUIDs) are low-noise amplifiers that are essential for the readouts of translation edge sensors(TESs). The linear flux range is an important parameter for SQUID amplifiers, especially those controlled by high-bandwidth digital flux-locked-loop circuits. A large linear flux range conduces to accurately measuring the input signal and also increasing the multiplexing factor in the time-division multiplexed(TDM) readout scheme of the TES array. In this work, we report that the linear flux range of an SQUID can be improved by using self-feedback effect. When the SQUID loop is designed to be asymmetric, a voltage-biased SQUID shows an asymmetric current–flux(I–Φ) response curve. The linear flux range is improved along the I–Φ curve with a shallow slope. The experimental results accord well with the numerical simulations. The asymmetric SQUID will be able to serve as a building block in the development of the TDM readout systems for large TES arrays.展开更多
基金supported by the National Basic Research Program of China(Grant No.2011CBA00106)the National Natural Science Foundation of China(Grant No.11074008)the Research Fund for the Doctoral Program of Higher Education,China(Grant No.20100001120006)
文摘We describe the fabrication of high performance YBa2Cu3O7-δ （YBCO） radio frequency （RF） superconducting quantum interference devices （SQUIDs）, which were prepared on 5 mm×5 mm LaAlO3 （LAO） substrates by employing stepedge junctions （SEJs） and in flip-chip configuration with 12 mm×12 mm resonators. The step in the substrate was produced by Ar ion etching with step angles ranging from 47° to 61°, which is steep enough to ensure the formation of grain boundaries （GBs） at the step edges. The YBCO film was deposited using the pulsed laser deposition （PLD） technique with a film thickness half of the height of the substrate step. The inductance of the SQUID washer was designed to be about 157 pH. Under these circumstances, high performance YBCO RF SQUIDs were successfully fabricated with a typical flux-voltage transfer ratio of 83 mV/φ0, a white flux noise of 29 μφ0/√Hz, and the magnetic field sensitivity as high as 80 fT/√Hz. These devices have been applied in magnetocardiography and geological surveys.
基金Supported by the Natural Science Foundation of China under Grant No.60677044
文摘We propose a scheme to generate a three-qubit three-IeveI singlet state in cavity QED, by placing three A-type SQUIDs in a single mode cavity. In this scheme, we make use of the interaction between the SQUIDs and cavity filed, and the classical pulses. The cavity fields are in vacuum state during the whole operation processes of creating the entanglement, and there is no quantum information transformation between the SQUIDs and cavity fields. Because of the advantage of the SQUID-cavity system, the quality factor of the cavity is greatly relaxed.
基金Supported by the National Research and Development Center for SuperconductivityFEUYT of State Educational Commission of China.
文摘We have developed a simple sintering system to prepare the yttria-stabilized-zirconia(YSZ)bicrystals.Grain-boundary junctions made from the epitaxial YBa_(2)Cu_(3)O_(7-δ) films on the bicrystal substrates demonstrated Josephson behavior.Using new square washer design,single-level magnetometer of dc superconducting quantum interference.device(SQUID)has been fabricated.Owing to the flux focusing effect of the large washer,the magnetic field sensitivity of the devices has been enhanced.The magnetic field resolution of the magnetometer is IpT/Hz^(1/2) at 10Hz,and increases to 3pT/Hz^(1/2) at 1Hz at 77K.
基金Supported by the National Research and Development Cent er for Superconductivity.
文摘Bicvystal Josephson junctions and direct current superconducting quantum inter ference devices(dc sQUIDs)were prepared on YBa_(2)Cu_(3)O_(7)(YBCO)thin films deposited on yttrium stabilized ZrO_(2) bicrystal substrates.The critical current densities J_(c)~2×10^(6)/cm^(2) for YBCO thin filmand(1-3)×10^(3)A/cm^(2) at boundaries were obtained at 77 K.For YBCO Josephson junctionmade on 28° misorientated boundary,the Shapiro steps were observed.The dc SQUID was madeon the 32° misorientated boundary junctions,which consisted of 40×40 m of loop and 2000×2000 pn planar superconductive flu.r focuser.The zoltage modulation depth of this SQUID was6 p.V,and the magnetic field sensitivity was estimated to be~2 pT/√Hz from the measurednoise level.
文摘Double-microbridge de superconducting quantum interference devices(SQUIDs)have been fabricated from the postannealed Y_(1)Ba_(2)Cu_(3)O_(y) and Tl_(2)-Ba_(2)Ca_(2)Cu_(3)O_(y) thin films by chemical etching and ion milling patterning technique.The applied magnetic field dependences of the voltage of the YBCO and TBCCO SQUIDs have been studied at temperature ranging from 4.2 to 23K and at 77K.The largest output voltage of the devices were 3.4μV/Φ_(0 )(at 5K)for YBCO and 60μV/Φ_(0)(at 77K)for TBCCO.The properties of the output of these devices have been discussed.
基金Project supported by the National Natural Science Foundation of China(Grant No.11653001)the National Basic Research Program of China(Grant No.2011CBA00304)Tsinghua University Initiative Scientific Research Program,China(Grant No.20131089314)
文摘The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with identical junctions and the series SQUIDs with different junctions were successfully fabricated. The Nb/Al-AlOx/Nb trilayer and input Nb coils were prepared by asputtering equipment. The SQUID devices were prepared by a sputtering and the lift-off method.Investigations by AFM, OM and SEM revealed the morphology and roughness of the Nb films and Nb/Al-AlOx/Nb trilayer.In addition, the current–voltage characteristics of the SQUID devices with identical junction and different junction areas were measured at 2.5 K in the He^3 refrigerator. The results show that the SQUID modulation depth is obviously affected by the junction area. The modulation depth obviously increases with the increase of the junction area in a certain range. It is found that the series SQUID with identical junction area has a transimpedance gain of 58 Ω approximately.
文摘Objective:To analyze the safety and effectiveness of the ethylene-vinyl alcohol copolymer(EVOH)liquid embolic agent Squid(Emboflu,Switzerland)for the treatment of brain arteriovenous malformations.Materials and procedures:Between April 2015 and July 2017,46 embolization treatments for brain arteriovenous malformations(BAVM)were performed in 25 patients using two Squid formulations(18 and 12).Six female and 19 male patients with a mean age of 34 years(range,9–62 years)were included.A total of 46 procedures were performed.The BAVMs were classified as Spetzler-Martin gradeⅡin 4 procedures,Ⅲin 27 procedures,and 1V in 15 procedures.Among the 25 patients,15 presented with hemorrhage,5 with seizures,and 5 with headache and neurology.The BAVMs were located in the temporal lobe in 5 patients,parietal lobe in 7 patients,frontal lobe in 3 patients,posterior fossa in 6 patients,basal ganglia in 3 patients,and parasagittal lobe in 1 patient.Results:The obliteration rate of the BAVMs ranged from 10%to 100%,with a mean of 33%.Most patients underwent their first or second embolization procedure.Four patients(8%)developed intracranial bleeding post procedure,with one death(2%).One patient(2%)experienced a seizure during the procedure;however,no intracranial bleeding was observed.Seven patients(15%)experienced perforations during catheter manipulation.One case(2%)of fractured catheter was recorded,but no significant complications were observed.The average volume of copolymer injected was 0.6 ml per nidus.Thirteen procedures used the Squid-12 formulation,29 procedures used the Squid-18 formulation,and 3 procedures used a combination of Squid-12 and-18 formulations.Conclusion:Squid is a safe and effective embolic agent for treating BAVMs.
基金Project supported by the Fund from China National Space Administration (CNSA) (Grant No. D050104)the Fund for Low Energy Gamma Ray Detection Research Based on SQUID Techniquethe Superconducting Electronics Facility (SELF) of Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences。
文摘Superconducting quantum interference devices(SQUIDs) are low-noise amplifiers that are essential for the readouts of translation edge sensors(TESs). The linear flux range is an important parameter for SQUID amplifiers, especially those controlled by high-bandwidth digital flux-locked-loop circuits. A large linear flux range conduces to accurately measuring the input signal and also increasing the multiplexing factor in the time-division multiplexed(TDM) readout scheme of the TES array. In this work, we report that the linear flux range of an SQUID can be improved by using self-feedback effect. When the SQUID loop is designed to be asymmetric, a voltage-biased SQUID shows an asymmetric current–flux(I–Φ) response curve. The linear flux range is improved along the I–Φ curve with a shallow slope. The experimental results accord well with the numerical simulations. The asymmetric SQUID will be able to serve as a building block in the development of the TDM readout systems for large TES arrays.
