Weak measurement has been shown to play important roles in the investigation of both fundamental and practical problems.Anomalous weak values are generally believed to be observed only when post-selection is performed...Weak measurement has been shown to play important roles in the investigation of both fundamental and practical problems.Anomalous weak values are generally believed to be observed only when post-selection is performed,i.e.,only a particular subset of the data is considered.Here,we experimentally demonstrate that an anomalous weak value can be obtained without discarding any data by performing a sequential weak measurement on a single-qubit system.By controlling the blazing density of the hologram on a spatial light modulator,the measurement strength can be conveniently controlled.Such an anomalous phenomenon disappears when the measurement strength of the first observable becomes strong.Moreover,we find that the anomalous weak value cannot be observed without post-selection when the sequential measurement is performed on each of the components of a two-qubit system,which confirms that the observed anomalous weak value is based on sequential weak measurement of two noncommutative operators.展开更多
基金National Key Research and Development Program of China(2017YFA0305200,2016YFA0302700,2017YFA0304100)National Natural Science Foundation of China(11774335,61327901,61490711,61725504,11821404,U19A2075,11605205)+8 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciences(2015317)Key Research Program of Frontier Sciences,Chinese Academy of Sciences(CAS)(QYZDY-SSW-SLH003)Science Foundation of the CAS(ZDRW-XH-2019-1)Anhui Initiative in Quantum Information Technologies(AHY060300,AHY020100)Fundamental Research Funds for the Central Universities(WK2030380017,WK2470000026)Natural Science Foundation of Chongqing(cstc2015jcyjA00021,cstc2018jcyjA X0656)Entrepreneurship and Innovation Support Program for Chongqing Overseas Returnees(cx2017134,cx2018040)Fund of CAS Key Laboratory of Microscale Magnetic ResonanceFund of CAS Key Laboratory of Quantum Information。
文摘Weak measurement has been shown to play important roles in the investigation of both fundamental and practical problems.Anomalous weak values are generally believed to be observed only when post-selection is performed,i.e.,only a particular subset of the data is considered.Here,we experimentally demonstrate that an anomalous weak value can be obtained without discarding any data by performing a sequential weak measurement on a single-qubit system.By controlling the blazing density of the hologram on a spatial light modulator,the measurement strength can be conveniently controlled.Such an anomalous phenomenon disappears when the measurement strength of the first observable becomes strong.Moreover,we find that the anomalous weak value cannot be observed without post-selection when the sequential measurement is performed on each of the components of a two-qubit system,which confirms that the observed anomalous weak value is based on sequential weak measurement of two noncommutative operators.
