We analyze the reading and initialization of a topological qubit encoded by Majorana fermions in one-dimensional semiconducting nanowires, weakly coupled to a single level quantum dot(QD). It is shown that when the Ma...We analyze the reading and initialization of a topological qubit encoded by Majorana fermions in one-dimensional semiconducting nanowires, weakly coupled to a single level quantum dot(QD). It is shown that when the Majorana fermions are fused by tuning gate voltage, the topological qubit can be read out directly through the occupation of the QD in an energy window. The initialization of the qubit can also be realized via adjusting the gate voltage on the QD, with the total fermion parity conserved. As a result, both reading and initialization processes can be achieved in an all-electrical way.展开更多
We propose a scheme to achieve a kind of nontrivial multipartite pair-wise controlled phase operation in a cavity QED setup. The operation implemented is of geometrical nature and is not sensitive to the thermal state...We propose a scheme to achieve a kind of nontrivial multipartite pair-wise controlled phase operation in a cavity QED setup. The operation implemented is of geometrical nature and is not sensitive to the thermal state of the cavity. In particular, we have managed to avoid the conventional dispersive coupling so that high speed gate operation is achieved which is very important in view of decoherence. We show that this multipartite pair-wise controlled phase operation makes the generation of two-dimensional cluster states very efficient.展开更多
Besides its fundamental importance, non-reciprocity has also found many potential applications in quantum technology. Recently, many quantum systems have been proposed to realize non-reciprocity, but stable non-recipr...Besides its fundamental importance, non-reciprocity has also found many potential applications in quantum technology. Recently, many quantum systems have been proposed to realize non-reciprocity, but stable non-reciprocal process is still experimentally difficult in general, due to the needed cyclical interactions in artificial systems or operational difficulties in solid state materials. Here, we propose a new kind of interaction induced non-reciprocal operation, based on the conventional stimulated-Raman-adiabatic-passage (STIRAP) setup, which removes the experimental difficulty of requiring cyclical interaction, and thus it is directly implementable in various quantum systems. Furthermore, we also illustrate our proposal on a chain of three coupled superconducting transmons, which can lead to a non-reciprocal circulator with high fidelity without a ring coupling configuration as in the previous schemes or implementations. Therefore, our protocol provides a promising way to explore fundamental non-reciprocal quantum physics as well as realize non-reciprocal quantum device.展开更多
We propose a class of n-variable Boolean functions which can be used to implement quantum secure multiparty computation.We also give an implementation of a special quantum secure multiparty computation protocol.An adv...We propose a class of n-variable Boolean functions which can be used to implement quantum secure multiparty computation.We also give an implementation of a special quantum secure multiparty computation protocol.An advantage of our protocol is that only 1 qubit is needed to compute the n-tuple pairwise AND function,which is more efficient comparing with previous protocols.We demonstrate our protocol on the IBM quantum cloud platform,with a probability of correct output as high as 94.63%.Therefore,our protocol presents a promising generalization in realization of various secure multipartite quantum tasks.展开更多
We investigate the entanglement dynamical behavior of two coupled qubits via a Heisenberg XX interaction,which are connected with two independent finite temperature heat baths.By numerical simulations of the quantum m...We investigate the entanglement dynamical behavior of two coupled qubits via a Heisenberg XX interaction,which are connected with two independent finite temperature heat baths.By numerical simulations of the quantum master equation,it is found that the interesting phenomena of entanglement sudden death (ESD) as well as sudden birth (ESB) appear during the evolution process for particular initial states.We also show that two critical temperatures T1 (determining that the quantum state is entangled or separable) and T2 (where maximal stationary entanglement can be observed) exist,and stationary entanglement exhibits a non-monotonic behavior as a function of the finite temperature noise strength.These results enlarge the domain of the reasonable experimental temperature where stationary entanglement can be observable.展开更多
We propose a scheme to achieve a kind of nontrivial two-qubit operation using controllable electrons in double-dot molecules coupled to a transmission line resonator.The implemented operation is geometrical in nature ...We propose a scheme to achieve a kind of nontrivial two-qubit operation using controllable electrons in double-dot molecules coupled to a transmission line resonator.The implemented operation is geometrical in nature and insensitive to the state of the transmission line resonator.In particular,we are able to avoid conventional dispersive coupling so that a high speed gate operation can be achieved,which is important in view of decoherence.Meanwhile,we are able to further generalize the operation to an arbitrary phase case by dynamic decoupling with two sequences.展开更多
It is shown that strong coupling of Bose–Einstein condensates to an optical cavity can be realized experimentally. With an additional driven microwave field, we show that a highly nonlinear coupling among atoms in a ...It is shown that strong coupling of Bose–Einstein condensates to an optical cavity can be realized experimentally. With an additional driven microwave field, we show that a highly nonlinear coupling among atoms in a Bose–Einstein condensate can be induced with the assistance of the cavity mode. With such interaction, we can investigate the generation of many body entangled states. In particularly, we show that multipartite entangled GHZ states can be obtained in such architecture with current available techniques.展开更多
基金Project supported by Anhui Provincial Natural Science Foundation, China （Grant No 03042401）, the Key Program of the Education Department of Anhui Province, China （Grant Nos 2002kj029zd and 2006kj070A）, and the Talent Foundation of Anhui University, China. 0ne of the authors, Xue Zheng-Yuan, is also supported by the Postgraduate Innovation Research Plan from Anhui university, China.
基金Supported by the National Natural Science Foundation of China under Grant No 10905024, and the Doctoral Startup Natural Science Foundation of Guangdong Province.
The authors thank Professor Zhu S. L. for useful suggestions.
基金Project supported by the National Basic Research Program of China(Grant Nos.2011CB922100,2011CBA00205,and 2013CB921804)the General Research Fund(GRF)of the Research Grants Council(RGC)of Hong Kong,China(Grant Nos.HKU7058/11P and HKU7045/13P)+6 种基金the Collaborative Research Fund(CRF)of the Research Grants Council(RGC)of Hong Kong,China(Grant No.HKU-8/11G)the University Research Committee(URC)Fund of the Hong Kong University(HKU),Chinathe National Natural Science Foundation of China(Grant Nos.11074111,11023002,and 11004065)the Priority Academic Program Development of Jiangsu Higher Education Institutions,Chinathe Program for New Century Excellent Talents in University of Ministry of Education of Chinathe Program for Changjiang Scholars and Innovative Research Team in University,Chinathe Fundamental Research Funds for the Central Universities of Ministry of Education of China
文摘We analyze the reading and initialization of a topological qubit encoded by Majorana fermions in one-dimensional semiconducting nanowires, weakly coupled to a single level quantum dot(QD). It is shown that when the Majorana fermions are fused by tuning gate voltage, the topological qubit can be read out directly through the occupation of the QD in an energy window. The initialization of the qubit can also be realized via adjusting the gate voltage on the QD, with the total fermion parity conserved. As a result, both reading and initialization processes can be achieved in an all-electrical way.
基金Project supported by the National Fundamental Research Program of China (Grant No. 2013CB921804)the National Natural Science Foundation of China(Grant No. 11004065)+1 种基金the Natural Science Foundation of Guangdong Province of China (Grant Nos. 10451063101006312 and S2011040000403)the Funds of the Education Department of Anhui Province of China (Grant Nos. KJ2010A323, 2010SQRL187, and KJ2012B075)
文摘We propose a scheme to achieve a kind of nontrivial multipartite pair-wise controlled phase operation in a cavity QED setup. The operation implemented is of geometrical nature and is not sensitive to the thermal state of the cavity. In particular, we have managed to avoid the conventional dispersive coupling so that high speed gate operation is achieved which is very important in view of decoherence. We show that this multipartite pair-wise controlled phase operation makes the generation of two-dimensional cluster states very efficient.
基金Project supported partially by the National Natural Science Foundation of China （Grant No 60678022）, the Doctoral Fund of Ministry of Education of China （Grant No 20060357008）. Anhui Provincial Natural Science Foundation （Grant No 070412060）, the Key Program of the Education, Department of Anhui Province （Grant No 2006KJ070A）, the Program of the Education, Department of Anhui Province （Grant No 2006KJ057B） and the Talent Foundation of Anhui University, Anhui Key Laboratory of Information Materials and Devices （Anhui University）.
基金Project supported by the Natural Science Foundation of the Education Department of Anhui Province, China （Grant Nos 2004kj005zd and 2005kj235） and Anhui Provincial Natural Science Foundation, China （Grant No 03042401） and the Talent Foundation of Anhui University, China.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874156 and 11904111)the Project funded by China Postdoctoral Science Foundation(Grant No.2019M652684).
文摘Besides its fundamental importance, non-reciprocity has also found many potential applications in quantum technology. Recently, many quantum systems have been proposed to realize non-reciprocity, but stable non-reciprocal process is still experimentally difficult in general, due to the needed cyclical interactions in artificial systems or operational difficulties in solid state materials. Here, we propose a new kind of interaction induced non-reciprocal operation, based on the conventional stimulated-Raman-adiabatic-passage (STIRAP) setup, which removes the experimental difficulty of requiring cyclical interaction, and thus it is directly implementable in various quantum systems. Furthermore, we also illustrate our proposal on a chain of three coupled superconducting transmons, which can lead to a non-reciprocal circulator with high fidelity without a ring coupling configuration as in the previous schemes or implementations. Therefore, our protocol provides a promising way to explore fundamental non-reciprocal quantum physics as well as realize non-reciprocal quantum device.
基金National Key R&D Program of China(Grant No.2017YFB0802400)National Natural Science Foundation of China(Grant Nos.61373171 and 11801564)+2 种基金Program for Excellent Young Talents in University of Anhui Province,China(Grant No.gxyq ZD2019060)Basic Research Project of Natural Science of Shaanxi Province,China(Grant Nos.2017JM6037 and 2017JQ1032)Key Project of Science Research of Anhui Province,China(Grant No.KJ2017A519)。
文摘We propose a class of n-variable Boolean functions which can be used to implement quantum secure multiparty computation.We also give an implementation of a special quantum secure multiparty computation protocol.An advantage of our protocol is that only 1 qubit is needed to compute the n-tuple pairwise AND function,which is more efficient comparing with previous protocols.We demonstrate our protocol on the IBM quantum cloud platform,with a probability of correct output as high as 94.63%.Therefore,our protocol presents a promising generalization in realization of various secure multipartite quantum tasks.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11004065 and 11105049Educational Com-mission of Hubei Province under Grant Nos Q20112501 and 2010C20.
文摘We investigate the entanglement dynamical behavior of two coupled qubits via a Heisenberg XX interaction,which are connected with two independent finite temperature heat baths.By numerical simulations of the quantum master equation,it is found that the interesting phenomena of entanglement sudden death (ESD) as well as sudden birth (ESB) appear during the evolution process for particular initial states.We also show that two critical temperatures T1 (determining that the quantum state is entangled or separable) and T2 (where maximal stationary entanglement can be observed) exist,and stationary entanglement exhibits a non-monotonic behavior as a function of the finite temperature noise strength.These results enlarge the domain of the reasonable experimental temperature where stationary entanglement can be observable.
基金Supported by the National Natural Science Foundation of China under Grant No 11004065the Natural Science Foundation of Guangdong Province(No 10451063101006312)+1 种基金the Key Project of the Education Department of Anhui Province(No KJ2010A323)the Startup Foundation of SCNU(No S53005).
文摘We propose a scheme to achieve a kind of nontrivial two-qubit operation using controllable electrons in double-dot molecules coupled to a transmission line resonator.The implemented operation is geometrical in nature and insensitive to the state of the transmission line resonator.In particular,we are able to avoid conventional dispersive coupling so that a high speed gate operation can be achieved,which is important in view of decoherence.Meanwhile,we are able to further generalize the operation to an arbitrary phase case by dynamic decoupling with two sequences.
基金Supported by the National Fundamental Research Program of China under Grant No.2013CB921804the Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT1243the Natural Science Foundation of Anhui Province under Grant No.1408085MA20
文摘It is shown that strong coupling of Bose–Einstein condensates to an optical cavity can be realized experimentally. With an additional driven microwave field, we show that a highly nonlinear coupling among atoms in a Bose–Einstein condensate can be induced with the assistance of the cavity mode. With such interaction, we can investigate the generation of many body entangled states. In particularly, we show that multipartite entangled GHZ states can be obtained in such architecture with current available techniques.
