In this paper, we report the observation and characterisation of a systematic error in the implementation of <em>U</em><sub>3</sub> gates in the IBM quantum computers. By measuring the effect o...In this paper, we report the observation and characterisation of a systematic error in the implementation of <em>U</em><sub>3</sub> gates in the IBM quantum computers. By measuring the effect of this gate for various rotation angles the error appears as an over-rotation, whose magnitude does not correlate with IBM’s cited errors calculated using Clifford randomized benchmarking. We propose a simple mitigation procedure to limit the effects of this error. We show that using a simple mitigation strategy one can obtain improved results in the observed value for the CHSH inequality, measured in a cloud-based quantum computer. This work highlights the utility of simple mitigation strategies for short-depth quantum circuits.展开更多
The 5-qubit quantum computer prototypes that IBM has given open access to on the cloud allow the implementation of real experiments on a quantum processor. We present the results obtained in five experimental tests pe...The 5-qubit quantum computer prototypes that IBM has given open access to on the cloud allow the implementation of real experiments on a quantum processor. We present the results obtained in five experimental tests performed on these computers: dense coding, quantum Fourier transforms, Bell’s inequality, Mermin’s inequalities (up to n=5) and the construction of the prime state . These results serve to assess the functioning of the IBM 5Q chips.展开更多
文摘In this paper, we report the observation and characterisation of a systematic error in the implementation of <em>U</em><sub>3</sub> gates in the IBM quantum computers. By measuring the effect of this gate for various rotation angles the error appears as an over-rotation, whose magnitude does not correlate with IBM’s cited errors calculated using Clifford randomized benchmarking. We propose a simple mitigation procedure to limit the effects of this error. We show that using a simple mitigation strategy one can obtain improved results in the observed value for the CHSH inequality, measured in a cloud-based quantum computer. This work highlights the utility of simple mitigation strategies for short-depth quantum circuits.
文摘The 5-qubit quantum computer prototypes that IBM has given open access to on the cloud allow the implementation of real experiments on a quantum processor. We present the results obtained in five experimental tests performed on these computers: dense coding, quantum Fourier transforms, Bell’s inequality, Mermin’s inequalities (up to n=5) and the construction of the prime state . These results serve to assess the functioning of the IBM 5Q chips.
