介绍了低介质损耗共面波导(CPW)传输线电容测量方法中的反射系数测量及线电容外推测量技术,成功提取了商用校准基片101-190C上传输线的线电容。根据线电容算法模型,以校准件及矢网内部接收机动态幅相精度不理想作为误差来源,采用蒙特卡...介绍了低介质损耗共面波导(CPW)传输线电容测量方法中的反射系数测量及线电容外推测量技术,成功提取了商用校准基片101-190C上传输线的线电容。根据线电容算法模型,以校准件及矢网内部接收机动态幅相精度不理想作为误差来源,采用蒙特卡罗仿真对线电容测量结果的不确定度进行了评定。最后将线电容用于多线TRL校准,与NIST标定结果更接近,在40 GHz频率范围内,反射系数模值相差小于±0.02,传输幅度模值相差小于±0.05 d B,传输相位相差小于±1°。展开更多
Based on the rapid experimental developments of circuit QED,we propose a feasible scheme to simulate the spin-boson model with superconducting circuits,which can be used to detect quantum Kosterlitz-Thouless(KT) phase...Based on the rapid experimental developments of circuit QED,we propose a feasible scheme to simulate the spin-boson model with superconducting circuits,which can be used to detect quantum Kosterlitz-Thouless(KT) phase transition.We design the spinboson model by using a superconducting phase qubit coupled to a semi-infinite transmission line,which is regarded as a bosonic reservoir with a continuum spectrum.By tuning the bias current or the coupling capacitance,the quantum KT transition can be directly detected through tomography measurement on the states of the phase qubit.We also estimate the experimental parameters using the numerical renormalization group method.展开更多
We propose a one-step method to prepare multi-qubit GHZ and W states with transmon qubits capacitively coupled to a superconducting transmission line resonator(TLR).Compared with the scheme firstly introduced by Wang ...We propose a one-step method to prepare multi-qubit GHZ and W states with transmon qubits capacitively coupled to a superconducting transmission line resonator(TLR).Compared with the scheme firstly introduced by Wang et al.[Phys.Rev.B 81(2010) 104524],our schemes have longer dephasing time and much shorter operation time because the transmon qubits we used are not only more robust to the decoherence and the unavoidable parameter variations,but also have much stronger coupling constant with TLR.Based on the favourable properties of transmons and TLR,our method is more feasible in experiment.展开更多
文摘介绍了低介质损耗共面波导(CPW)传输线电容测量方法中的反射系数测量及线电容外推测量技术,成功提取了商用校准基片101-190C上传输线的线电容。根据线电容算法模型,以校准件及矢网内部接收机动态幅相精度不理想作为误差来源,采用蒙特卡罗仿真对线电容测量结果的不确定度进行了评定。最后将线电容用于多线TRL校准,与NIST标定结果更接近,在40 GHz频率范围内,反射系数模值相差小于±0.02,传输幅度模值相差小于±0.05 d B,传输相位相差小于±1°。
基金supported by the National Natural Science Foundation of China (Grant Nos. 11004065,11104057 and 11125417)the Natural Science Foundation of Guangdong Province (Grant No.10451063101006312)+1 种基金the State Key Program for Basic Research of China(Grant No. 2011CB922104)the GRF and CRF of the RGC of Hong Kong
文摘Based on the rapid experimental developments of circuit QED,we propose a feasible scheme to simulate the spin-boson model with superconducting circuits,which can be used to detect quantum Kosterlitz-Thouless(KT) phase transition.We design the spinboson model by using a superconducting phase qubit coupled to a semi-infinite transmission line,which is regarded as a bosonic reservoir with a continuum spectrum.By tuning the bias current or the coupling capacitance,the quantum KT transition can be directly detected through tomography measurement on the states of the phase qubit.We also estimate the experimental parameters using the numerical renormalization group method.
基金Supported by the National Natural Science Foundation of China under Grant No. 10947017/A05Key Lab of Novel Thin Film Solar Cells (KF200912)Graduates’ Innovative Scientific Research Project of Zhejiang Province under Grant No. 2011831
文摘We propose a one-step method to prepare multi-qubit GHZ and W states with transmon qubits capacitively coupled to a superconducting transmission line resonator(TLR).Compared with the scheme firstly introduced by Wang et al.[Phys.Rev.B 81(2010) 104524],our schemes have longer dephasing time and much shorter operation time because the transmon qubits we used are not only more robust to the decoherence and the unavoidable parameter variations,but also have much stronger coupling constant with TLR.Based on the favourable properties of transmons and TLR,our method is more feasible in experiment.
