In superconducting circuit,microwave resonators and capacitors are crucial components,and their quality has a strong impact on circuit performance.Here we develop a novel wet etching process to define these two compon...In superconducting circuit,microwave resonators and capacitors are crucial components,and their quality has a strong impact on circuit performance.Here we develop a novel wet etching process to define these two components using common photoresist developer as etchant.This method reduces subsequent steps and can be completed immediately after development.By measuring the internal quality factor of resonators,we show that it is possible to achieve similar or better performance when compared with samples made by standard etching processes.This easy-to-implement method may boost the yield hence providing an alternative fabrication process for microwave resonators and capacitors.展开更多
We demonstrate an active reset protocol in a superconducting quantum circuit.The thermal population on the excited state of a transmon qubit is reduced through driving the transitions between the qubit and an ancillar...We demonstrate an active reset protocol in a superconducting quantum circuit.The thermal population on the excited state of a transmon qubit is reduced through driving the transitions between the qubit and an ancillary qubit.Furthermore,we investigate the efficiency of this approach at different temperatures.The result shows that population in the first excited state can be dropped from 7%to 2.55%in 27 ns at 30 m K.The efficiency improves as the temperature increases.Compared to other schemes,our proposal alleviates the requirements for measurement procedure and equipment.With the increase of qubit integration,the fast reset technique holds the promise of improving the fidelity of quantum control.展开更多
A semi-infinite waveguide acts as a mirror and helps protect the qubit in front of it from decoherence.Here,we investigate the interference effect in an open waveguide consisting of resonators with different decay rat...A semi-infinite waveguide acts as a mirror and helps protect the qubit in front of it from decoherence.Here,we investigate the interference effect in an open waveguide consisting of resonators with different decay rates.We find that a lossy resonator works as a mirror and changes the effective decay rate of the other.The spontaneous radiation of qubit is related to its environment,and we can control it by arranging the lossy resonator's position or frequency.Our approach helps improving the qubit performance,as well as the quantum gate fidelities.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0301802)the National Natural Science Foundation of China(Grant Nos.61521001 and 11890704)the Key R&D Program of Guangdong Province,China(Grant No.2018B030326001).
文摘In superconducting circuit,microwave resonators and capacitors are crucial components,and their quality has a strong impact on circuit performance.Here we develop a novel wet etching process to define these two components using common photoresist developer as etchant.This method reduces subsequent steps and can be completed immediately after development.By measuring the internal quality factor of resonators,we show that it is possible to achieve similar or better performance when compared with samples made by standard etching processes.This easy-to-implement method may boost the yield hence providing an alternative fabrication process for microwave resonators and capacitors.
基金the National Key R&D Program of China(Grant No.2016YFA0301802)the National Natural Science Foundation of China(Grant Nos.61521001,11474153,and 11890704)the Key R/D Program of Guangdong Province,China(Grant No.2018B030326001)。
文摘We demonstrate an active reset protocol in a superconducting quantum circuit.The thermal population on the excited state of a transmon qubit is reduced through driving the transitions between the qubit and an ancillary qubit.Furthermore,we investigate the efficiency of this approach at different temperatures.The result shows that population in the first excited state can be dropped from 7%to 2.55%in 27 ns at 30 m K.The efficiency improves as the temperature increases.Compared to other schemes,our proposal alleviates the requirements for measurement procedure and equipment.With the increase of qubit integration,the fast reset technique holds the promise of improving the fidelity of quantum control.
基金the National Key R&D Progarm of China(Grant No.2016YFA0301802)the National Natural Science Foundation of China(Grant Nos.61521001,12074179,and 11890704)the Key R&D Program of Guangdong Province,China(Grant No.2018B030326001)。
文摘A semi-infinite waveguide acts as a mirror and helps protect the qubit in front of it from decoherence.Here,we investigate the interference effect in an open waveguide consisting of resonators with different decay rates.We find that a lossy resonator works as a mirror and changes the effective decay rate of the other.The spontaneous radiation of qubit is related to its environment,and we can control it by arranging the lossy resonator's position or frequency.Our approach helps improving the qubit performance,as well as the quantum gate fidelities.
