Instead of projective measurement, we use weak measurement to define quantum and geometric discords, and compare them with the normal quantum and geometric discords based on the projective measurement in noninertial f...Instead of projective measurement, we use weak measurement to define quantum and geometric discords, and compare them with the normal quantum and geometric discords based on the projective measurement in noninertial frames. We find that using weak measurement to define quantum discord we can capture more quantum correlations compared with the projective measurement, so calling it super quantum discord. However, we note that the geometric discord based on the weak measurements becomes smaller, so we name it inferior “geometric discord”. We also show that, although both the super quantum discord and the inferior “geometric discord” decrease with the increase of observer’s acceleration, the super quantum discord/inferior “geometric discord” increases/decreases as the measurements become weak. These differences reveal that the definitions of the quantum and geometric discords are not too concordant with each other.展开更多
Super-quantum discord（SQD） with weak measurement is regarded as a kind of quantum correlation in quantum information processing. We compare and analyze the dynamical evolutions of SQD, quantum discord（QD）, and qua...Super-quantum discord（SQD） with weak measurement is regarded as a kind of quantum correlation in quantum information processing. We compare and analyze the dynamical evolutions of SQD, quantum discord（QD）, and quantum entanglement（QE） between two qubits in the correlated dephasing environmental model. The results indicate that（i） owing to the much smaller influence of weak measurement on the coherence of the system than that of von Neumann projection measurement, SQD with weak measurement is larger than QD, and（ii） dynamical evolution of QD or QE monotonically goes to zero with time, while SQD monotonically tends to a stable value and a freezing phenomenon occurs. The stable value after freezing mainly depends on the measurement strength and the purity of the initial quantum state.展开更多
The dynamics of quantum discord for two qubits independently interacting with dephasing reservoirs have been studied recently.The authors [Phys.Rev.A 88(2013) 034304] found that for some Bell-diagonal states(BDS)which...The dynamics of quantum discord for two qubits independently interacting with dephasing reservoirs have been studied recently.The authors [Phys.Rev.A 88(2013) 034304] found that for some Bell-diagonal states(BDS)which interact with their environments the calculation of quantum discord could experience a sudden transition in its dynamics,this phenomenon is known as the sudden change.Here in the present paper,we analyze the dynamics of normal quantum discord and super quantum discord for tripartite Bell-diagonal states independently interacting with dephasing reservoirs.Then,we find that basis change does not necessary mean sudden change of quantum correlations.展开更多
In our study of super quantum discord between two excitonic qubits inside a coupled semiconductor quantum dots system,our primary focus is to uncover the impact of weak measurement on its quantum characteristics.To ac...In our study of super quantum discord between two excitonic qubits inside a coupled semiconductor quantum dots system,our primary focus is to uncover the impact of weak measurement on its quantum characteristics.To achieve this,we analyze how varying the measurement strength x,affects this super quantum correlation in the presence of thermal effects.Additionally,we assess the effect of this variation on the system's evolution against its associated quantum parameters;external electric fields,exciton-exciton dipole interaction energy and F?rster interaction.Our findings indicate that adjusting x to smaller values effectively enhances the super quantum correlation,making weak measurements act as a catalyst.This adjustment ensures its robustness against thermal effects while preserving the non-classical attributes of the system.Furthermore,our study unveils that the effect of weak measurements on this latter surpasses the quantum effects associated with the system.Indeed,manipulating the parameter x allows the weak measurement to function as a versatile tool for modulating quantum characteristics and controlling exciton-exciton interactions within the coupled semiconductor quantum dots system.展开更多
文摘Instead of projective measurement, we use weak measurement to define quantum and geometric discords, and compare them with the normal quantum and geometric discords based on the projective measurement in noninertial frames. We find that using weak measurement to define quantum discord we can capture more quantum correlations compared with the projective measurement, so calling it super quantum discord. However, we note that the geometric discord based on the weak measurements becomes smaller, so we name it inferior “geometric discord”. We also show that, although both the super quantum discord and the inferior “geometric discord” decrease with the increase of observer’s acceleration, the super quantum discord/inferior “geometric discord” increases/decreases as the measurements become weak. These differences reveal that the definitions of the quantum and geometric discords are not too concordant with each other.
基金Project supported by the National Natural Science Foundation of China(Grant No.11264015)
文摘Super-quantum discord（SQD） with weak measurement is regarded as a kind of quantum correlation in quantum information processing. We compare and analyze the dynamical evolutions of SQD, quantum discord（QD）, and quantum entanglement（QE） between two qubits in the correlated dephasing environmental model. The results indicate that（i） owing to the much smaller influence of weak measurement on the coherence of the system than that of von Neumann projection measurement, SQD with weak measurement is larger than QD, and（ii） dynamical evolution of QD or QE monotonically goes to zero with time, while SQD monotonically tends to a stable value and a freezing phenomenon occurs. The stable value after freezing mainly depends on the measurement strength and the purity of the initial quantum state.
文摘The dynamics of quantum discord for two qubits independently interacting with dephasing reservoirs have been studied recently.The authors [Phys.Rev.A 88(2013) 034304] found that for some Bell-diagonal states(BDS)which interact with their environments the calculation of quantum discord could experience a sudden transition in its dynamics,this phenomenon is known as the sudden change.Here in the present paper,we analyze the dynamics of normal quantum discord and super quantum discord for tripartite Bell-diagonal states independently interacting with dephasing reservoirs.Then,we find that basis change does not necessary mean sudden change of quantum correlations.
文摘In our study of super quantum discord between two excitonic qubits inside a coupled semiconductor quantum dots system,our primary focus is to uncover the impact of weak measurement on its quantum characteristics.To achieve this,we analyze how varying the measurement strength x,affects this super quantum correlation in the presence of thermal effects.Additionally,we assess the effect of this variation on the system's evolution against its associated quantum parameters;external electric fields,exciton-exciton dipole interaction energy and F?rster interaction.Our findings indicate that adjusting x to smaller values effectively enhances the super quantum correlation,making weak measurements act as a catalyst.This adjustment ensures its robustness against thermal effects while preserving the non-classical attributes of the system.Furthermore,our study unveils that the effect of weak measurements on this latter surpasses the quantum effects associated with the system.Indeed,manipulating the parameter x allows the weak measurement to function as a versatile tool for modulating quantum characteristics and controlling exciton-exciton interactions within the coupled semiconductor quantum dots system.
