Complete Bell-state Analysis for Superconducting-quantum-interference-Gadget Qubits With Transitionless Tracking Algorithm > 자유게시판

On this paper, we suggest a protocol for complete Bell-state evaluation for 2 superconducting-quantum-interference-machine qubits. The Bell-state analysis may very well be accomplished through the use of a sequence of microwave pulses designed by the transitionless tracking algorithm, which is an helpful methodology in the technique of shortcut to adiabaticity. After the whole process, the data for distinguishing four Bell states will be encoded on two auxiliary qubits, whereas the Bell states keep unchanged. One can learn out the knowledge by detecting the auxiliary qubits. Thus the Bell-state analysis is nondestructive. The numerical simulations show that the protocol possesses high success probability of distinguishing each Bell state with present experimental iTagPro technology even when decoherence is taken into consideration. Thus, the protocol might have potential purposes for the knowledge readout in quantum communications and iTagPro technology quantum computations in superconducting quantum networks. Entanglement is a fundamental concept in quantum data science. It supplies possibility to test quantum nonlocality in opposition to local hidden principle BellPhysics1 ; Greenberger ; DurPRA62 , and likewise performs a key position in varied quantum info duties KarlssonPRA58 ; DFGPRA72 ; EkertPRL67 ; DFGPRA68 ; BennettPRL69 ; LXSPRA65 ; SYBPRA81I .

Therefore, preparing DZJPRA74 ; DLMPRL90 , iTagPro technology transferring WTJPRA85 ; HCYPRB83 and purifying RBCPRA90 ; PanNat410 all sorts of entangled states in different bodily programs turn out to be sizzling matters in quantum info processing (QIP). As Bell states of two qubits are simple to be obtained and iTagPro technology manipulated, they've been employed as the information carriers in quantum communications and quantum computations EkertPRL67 ; BennettPRL69 ; BennettPRL68 . Thus when using Bell states as data carriers, studying out quantum info encoded on Bell states is an indispensable process, which greatly motivated the researches on the Bell-state analysis. In the beginning, researchers mainly paid their attentions on the Bell-state analysis for polarized photons with liner optical parts MattlePRL76 ; HouwelingenPRL96 . But sadly, iTagPro technology it have been confirmed by protocols VaidmanPRA59 ; CalsamigliaPRA65 that the Bell-state analysis with solely linear optical ingredient have optimum success probability of 0.5. Besides, the Bell-state analysis usually destroys the entanglement which causes the waste of bodily resources. Therefore, to realize complete and nondestructive Bell-state analysis and to take advantage of the advantages of different bodily methods, researchers have turned their attentions on Bell states in various techniques by making use of many new strategies, reminiscent of nonlinearities and hyperentanglement.

Until now, complete and nondestructive Bell-state evaluation for photons SYBPRA81II ; SYBPRA82 ; BarbieriPRA75 ; WTJPRA86 ; RBCOE20 ; BonatoPRL104 ; XYJOSAB31 , atoms HYCPB19 , ItagPro spins inside quantum dots WHRIJTP52 ; KYHAPB119 and nitrogen-vacancy centers LJZIJTP56 have been reported. In recent times, the superconducting system has been developed rather a lot, and is now deemed as a very promising candidate to implement quantum information tasks MakhlinRMP73 ; XZLRMP85 ; VionSci296 ; YYSci296 ; YCPPRL92 ; YCPPRA67 ; YCPPRA74 ; YCPPRA82 ; ClarkeNature453 ; DevoretADP16 ; YCPPRA86 ; BlaisPRA69 ; WallraffNature431 ; YCPPRA87 ; ChiorescuNature431 ; SteinbachPRL87 ; FilippPRL102 ; BialczakNP6 ; YamamotoPRB82 ; ReedPRL105 ; MajerNature449 ; DiCarloNature460 ; SchmidtADP525 ; StrauchPRL105 ; KochPRA76 , because it possesses many advantages. Superconducting qubits, including section qubits, change qubits, flux qubits, and iTagPro technology so on., are excellent with their comparatively long decoherence time ClarkeNature453 and perfect scalability VionSci296 ; YYSci296 ; ChiorescuNature431 . 1) The positions of SQUID qubits in a cavity are fixed. That makes them holds superiority in contrast with impartial atoms, which requires to be controlled the centers of mass movement in a cavity.

YCPPRL92 ; YCPPRA67 . 2) When inserting SQUID qubits into a superconducting cavity, decoherence induced because of the external setting could be greatly suppressed for the reason that superconducting cavity could possibly be considered as the magnetic shield for SQUID qubits YCPPRA67 . 3) The strong-coupling restrict of the cavity QED could be simply realized for SQUID qubits embedded in a cavity, while it's difficult to be realized with atoms YCPPRL92 . 4) The level structure of each individual SQUID qubit might be adjusted easily YCPPRL92 . The nice benefits of SQUID qubits make them engaging decisions to implement quantum information duties. Up to now, SQUID qubits have been extensively used in entanglement preparations YCPPRL92 ; YCPPRA67 ; DZJPRA74 ; SKHPRA75 , information transfers YCPPRL92 ; YCPPRA67 , logic gates YCPPRA67 . However, Bell-state analysis for SQUID qubits nonetheless has loads room for ItagPro researches. On the other hand, when choosing superconducting system because the platform for QIP, an ineluctable question is to design microwave pulses driving superconducting qubits to complete numerous operations.