By means of the nuclear parton distributions determined without the fixed-target Drell-Yan experimental data and the analytic expression of quenching weight based on the BDMPS formalism,next-to-leading order analyses ...By means of the nuclear parton distributions determined without the fixed-target Drell-Yan experimental data and the analytic expression of quenching weight based on the BDMPS formalism,next-to-leading order analyses were performed on the Drell-Yan differential cross section ratios from the Fermilab E906 and E866 collaborations.It was found that the results calculated only with the nuclear effects of the parton distribution were not in agreement with the E866 and E906 experimental data.The incoming parton energy loss effect cannot be ignored in the nuclear Drell-Yan reactions.The predicted results indicate that,with the quark transport coefficient as a constant,the suppression due to the target nuclear geometry effect is approximately 16.85%for the quark transport coefficient.It was shown that we should consider the target nuclear geometry effect in studying the Drell-Yan reaction on nuclear targets.On the basis of the Bjorken variable and scale dependence of the quark transport coefficient,the atomic mass dependence was incorporated.The quark transport coefficient was determined as a function of the atomic mass,Bjorken variablex_(2),and scale Q^(2)by the global fit of the experimental data.The determined constant factor q_(0)of the quark transport coefficient is 0.062±0.006 GeV^(2)/fm.It was found that the atomic mass dependence has a significant impact on the constant factor q_(0)in the quark transport coefficient in cold nuclear matter.展开更多
Surface charge transfer doping has been widely utilized to tune the electronic and optical properties of semiconductor photodetectors based on low-dimensional materials.Although many studies have been conducted on the...Surface charge transfer doping has been widely utilized to tune the electronic and optical properties of semiconductor photodetectors based on low-dimensional materials.Although many studies have been conducted on the performance(response time,responsivity,etc.)of doped photodetectors and their mechanisms,they merely examined a specific thickness and did not systematically explore the dependence of doping effects on the number of layers.This work performs a series of investigations on ReS_(2)photodetectors with different numbers of layers and demonstrates that the p-dopant tetrafluorotetracyanoquinodimethane(F_(4)-TCNQ)converts the deep trap states into recombination centers for few-layer ReS_(2)and induces a vertical p-n junction for thicker ReS_(2).A response time of 200 ms is observed in the decorated 2-layer ReS_(2)photodetector,more than two orders of magnitude faster than the response of the pristine photodetector,due to the disappearance of deep trap states.A current rectification ratio of 30 in the F_(4)-TCNQ-decorated sandwiched ReS_(2)device demonstrates the formation of a vertical p-n junction in a thicker ReS_(2)device.The responsivity is as high as 2,000 A/W owing to the strong carrier separation of the p-n junction.Different thicknesses of ReS_(2)enable switching of the prominent operating mechanism between transforming deep trap states into recombination centers and forming a vertical p-n junction.The thicknessdependent doping effect of a two-dimensional material serves as a new mechanism and provides a scheme toward improving the performance of other semiconductor devices,especially optical and electronic devices based on low-dimensional materials.展开更多
基金Supported in part by the National Natural Science Foundation of China(11975090,11575052)。
文摘By means of the nuclear parton distributions determined without the fixed-target Drell-Yan experimental data and the analytic expression of quenching weight based on the BDMPS formalism,next-to-leading order analyses were performed on the Drell-Yan differential cross section ratios from the Fermilab E906 and E866 collaborations.It was found that the results calculated only with the nuclear effects of the parton distribution were not in agreement with the E866 and E906 experimental data.The incoming parton energy loss effect cannot be ignored in the nuclear Drell-Yan reactions.The predicted results indicate that,with the quark transport coefficient as a constant,the suppression due to the target nuclear geometry effect is approximately 16.85%for the quark transport coefficient.It was shown that we should consider the target nuclear geometry effect in studying the Drell-Yan reaction on nuclear targets.On the basis of the Bjorken variable and scale dependence of the quark transport coefficient,the atomic mass dependence was incorporated.The quark transport coefficient was determined as a function of the atomic mass,Bjorken variablex_(2),and scale Q^(2)by the global fit of the experimental data.The determined constant factor q_(0)of the quark transport coefficient is 0.062±0.006 GeV^(2)/fm.It was found that the atomic mass dependence has a significant impact on the constant factor q_(0)in the quark transport coefficient in cold nuclear matter.
基金This work was supported by the National Natural Science Foundation of China(No.61904043)the Natural Science Foundation of Zhejiang Province(No.LQ19A040009).
文摘Surface charge transfer doping has been widely utilized to tune the electronic and optical properties of semiconductor photodetectors based on low-dimensional materials.Although many studies have been conducted on the performance(response time,responsivity,etc.)of doped photodetectors and their mechanisms,they merely examined a specific thickness and did not systematically explore the dependence of doping effects on the number of layers.This work performs a series of investigations on ReS_(2)photodetectors with different numbers of layers and demonstrates that the p-dopant tetrafluorotetracyanoquinodimethane(F_(4)-TCNQ)converts the deep trap states into recombination centers for few-layer ReS_(2)and induces a vertical p-n junction for thicker ReS_(2).A response time of 200 ms is observed in the decorated 2-layer ReS_(2)photodetector,more than two orders of magnitude faster than the response of the pristine photodetector,due to the disappearance of deep trap states.A current rectification ratio of 30 in the F_(4)-TCNQ-decorated sandwiched ReS_(2)device demonstrates the formation of a vertical p-n junction in a thicker ReS_(2)device.The responsivity is as high as 2,000 A/W owing to the strong carrier separation of the p-n junction.Different thicknesses of ReS_(2)enable switching of the prominent operating mechanism between transforming deep trap states into recombination centers and forming a vertical p-n junction.The thicknessdependent doping effect of a two-dimensional material serves as a new mechanism and provides a scheme toward improving the performance of other semiconductor devices,especially optical and electronic devices based on low-dimensional materials.
