Anyons can be used to realize quantum computation, because they are two-level systems in two dimensions. In this paper, we propose a scheme to simulate single-qubit gates and CNOT gate using Abelian anyons in the Kita...Anyons can be used to realize quantum computation, because they are two-level systems in two dimensions. In this paper, we propose a scheme to simulate single-qubit gates and CNOT gate using Abelian anyons in the Kitaev model. Two pairs of anyons （six spins） are used to realize single-qubit gates, while ten spins are needed for the CNOT gate. Based on these quantum gates, we show how to realize the Grover algorithm in a two-qubit system.展开更多
We test a new four-qubit entangled state by the former Bell-like inequalities and find that it violates these inequalities,but not maximally.According to this entangled state,we build a new Bell-like inequality,which ...We test a new four-qubit entangled state by the former Bell-like inequalities and find that it violates these inequalities,but not maximally.According to this entangled state,we build a new Bell-like inequality,which is violated by this new state maximally.We also determine the nonlocality of some other four-qubit states by the new inequality.It is found that the new inequality acts as a strong entanglement witness for the new state.This can be used to test new entangled states experimentally.展开更多
Two tripartite schemes are put forward with shared entanglements and Local Operation and Classical Communication (LOCC) for sharing an operation on a remote target sate.The first scheme uses a Bell and a symmetric W s...Two tripartite schemes are put forward with shared entanglements and Local Operation and Classical Communication (LOCC) for sharing an operation on a remote target sate.The first scheme uses a Bell and a symmetric W states as quantum channels,while the second replaces the symmetric W state by an asymmetric one.Both schemes are treated and compared from the aspects of quantum resource consumption,operation complexity,classical resource consumption,success probability and efficiency.It is found that the latter scheme is better than the former one.Particularly,the sharing can be achieved only probabilistically with the first scheme deterministically with the second one.展开更多
We study the Bell's inequality and multipartite entanglement generation for initially maximally entangled states of free Dirac field in a non inertial frame and asymptotically flat Robertson–Walker space-time.For...We study the Bell's inequality and multipartite entanglement generation for initially maximally entangled states of free Dirac field in a non inertial frame and asymptotically flat Robertson–Walker space-time.For two qubit case,we show that the Bell's inequality always is violated as measured by the accelerated observers which are in the causally connected regions.On the other hand,for those observers in the causally disconnected regions inequality is not violated for any values of acceleration.The generated three qubit state from two qubit state due to acceleration of one parties has a zero 3-tangle.For a three qubit state,the inequality violated for measurements done by both causally connected and disconnected observers.Initially GHZ state with non zero 3-tangle,in accelerated frame,transformed to a four qubit state with vanishing 4-tangle value.On the other hand,for a W-state with zero 3-tangle,in non inertial frame,transformed to a four qubit state with a non-zero 4-tangle acceleration dependent.In an expanding space-time with asymptotically flat regions,for an initially maximally entangled state,the maximum value of violation of Bell's inequality in the far past decreased in the far future due to cosmological particle creation.For some initially maximally entangled states,the generated four qubit state due to expansion of space-time,has non vanishing 4-tangle.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 10874098the National Basic Research Program of China under Grant Nos. 2009CB929402, 2011CB9216002the Specialized Research Fund for the Doctoral Program of Education Ministry of China under Grant No. 20060003048
文摘Anyons can be used to realize quantum computation, because they are two-level systems in two dimensions. In this paper, we propose a scheme to simulate single-qubit gates and CNOT gate using Abelian anyons in the Kitaev model. Two pairs of anyons （six spins） are used to realize single-qubit gates, while ten spins are needed for the CNOT gate. Based on these quantum gates, we show how to realize the Grover algorithm in a two-qubit system.
基金supported by the Natural Science Basis Research Plan in Shaanxi Province of China (Grant No. 2013JM1009)
文摘We test a new four-qubit entangled state by the former Bell-like inequalities and find that it violates these inequalities,but not maximally.According to this entangled state,we build a new Bell-like inequality,which is violated by this new state maximally.We also determine the nonlocality of some other four-qubit states by the new inequality.It is found that the new inequality acts as a strong entanglement witness for the new state.This can be used to test new entangled states experimentally.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20103401110007National Natural Science Foundation of China under Grant Nos.10874122,10975001,51072002,and 51272003+1 种基金the Program for Excellent Talents at the University of Guangdong Province(Guangdong Teacher Letter[1010]No.79)the 211 Project of Anhui University
文摘Two tripartite schemes are put forward with shared entanglements and Local Operation and Classical Communication (LOCC) for sharing an operation on a remote target sate.The first scheme uses a Bell and a symmetric W states as quantum channels,while the second replaces the symmetric W state by an asymmetric one.Both schemes are treated and compared from the aspects of quantum resource consumption,operation complexity,classical resource consumption,success probability and efficiency.It is found that the latter scheme is better than the former one.Particularly,the sharing can be achieved only probabilistically with the first scheme deterministically with the second one.
基金Islamic Azad University,Khorram Branch,for Financial support
文摘We study the Bell's inequality and multipartite entanglement generation for initially maximally entangled states of free Dirac field in a non inertial frame and asymptotically flat Robertson–Walker space-time.For two qubit case,we show that the Bell's inequality always is violated as measured by the accelerated observers which are in the causally connected regions.On the other hand,for those observers in the causally disconnected regions inequality is not violated for any values of acceleration.The generated three qubit state from two qubit state due to acceleration of one parties has a zero 3-tangle.For a three qubit state,the inequality violated for measurements done by both causally connected and disconnected observers.Initially GHZ state with non zero 3-tangle,in accelerated frame,transformed to a four qubit state with vanishing 4-tangle value.On the other hand,for a W-state with zero 3-tangle,in non inertial frame,transformed to a four qubit state with a non-zero 4-tangle acceleration dependent.In an expanding space-time with asymptotically flat regions,for an initially maximally entangled state,the maximum value of violation of Bell's inequality in the far past decreased in the far future due to cosmological particle creation.For some initially maximally entangled states,the generated four qubit state due to expansion of space-time,has non vanishing 4-tangle.
