In blind quantum computation(BQC),a client with weak quantum computation capabilities is allowed to delegate its quantum computation tasks to a server with powerful quantum computation capabilities,and the inputs,algo...In blind quantum computation(BQC),a client with weak quantum computation capabilities is allowed to delegate its quantum computation tasks to a server with powerful quantum computation capabilities,and the inputs,algorithms and outputs of the quantum computation are confidential to the server.Verifiability refers to the ability of the client to verify with a certain probability whether the server has executed the protocol correctly and can be realized by introducing trap qubits into the computation graph state to detect server deception.The existing verifiable universal BQC protocols are analyzed and compared in detail.The XTH protocol(proposed by Xu Q S,Tan X Q,Huang R in 2020),a recent improvement protocol of verifiable universal BQC,uses a sandglass-like graph state to further decrease resource expenditure and enhance verification capability.However,the XTH protocol has two shortcomings:limitations in the coloring scheme and a high probability of accepting an incorrect computation result.In this paper,we present an improved version of the XTH protocol,which revises the limitations of the original coloring scheme and further improves the verification ability.The analysis demonstrates that the resource expenditure is the same as for the XTH protocol,while the probability of accepting the wrong computation result is reduced from the original minimum(0.866)^(d*)to(0.819)^(d^(*)),where d;is the number of repeated executions of the protocol.展开更多
We describe a scheme for universal quantum computation with Majorana fermions. We investigate two possible dissipative couplings of Majorana fermions to external systems, including metallic leads and local phonons. Wh...We describe a scheme for universal quantum computation with Majorana fermions. We investigate two possible dissipative couplings of Majorana fermions to external systems, including metallic leads and local phonons. While the dissipation when coupling to metallic leads to uninteresting states for the Majorana fermions, we show that coupling the Majorana fermions to local phonons allows to generate arbitrary dissipations and therefore universal quantum operations on a single QuBit that can be enhanced by additional two-QuBit operations.展开更多
Neutral atomic tweezer arrays have become a promising platform for quantum computation,which possess rich degrees of freedom(DoFs)as an important resource for encoding quantum information.We explore the DoF quantum re...Neutral atomic tweezer arrays have become a promising platform for quantum computation,which possess rich degrees of freedom(DoFs)as an important resource for encoding quantum information.We explore the DoF quantum resource in a ladder-shaped atomic tweezer array and propose a scheme of high-dimensional universal quantum computation.This scheme encodes qubits to two degrees of freedom of a single atom,namely the motional(Mo)and the site-occupation(SO)DoFs,which allows one atom to carry two qubits and results in a two-layer qubit architecture.The single-qubit rotational gates on Mo-and SO-qubits,as well as the intra-and inter-DoF Controlled-NOT(CNOT)gates are designed,and the crosstalk between qubits encoded with different DoFs is particularly addressed and compensated by the strategy composed of the detuning engineering and multi-chromatic Hamiltonian modulation.Quantum circuits are assembled from these gates in the ladder-shaped atomic array,generating the hyper and hyper-hybrid entangled states between the Mo and SO DoFs.Our work paves the way for high-dimensional quantum computation with multiple DoFs.展开更多
文摘In blind quantum computation(BQC),a client with weak quantum computation capabilities is allowed to delegate its quantum computation tasks to a server with powerful quantum computation capabilities,and the inputs,algorithms and outputs of the quantum computation are confidential to the server.Verifiability refers to the ability of the client to verify with a certain probability whether the server has executed the protocol correctly and can be realized by introducing trap qubits into the computation graph state to detect server deception.The existing verifiable universal BQC protocols are analyzed and compared in detail.The XTH protocol(proposed by Xu Q S,Tan X Q,Huang R in 2020),a recent improvement protocol of verifiable universal BQC,uses a sandglass-like graph state to further decrease resource expenditure and enhance verification capability.However,the XTH protocol has two shortcomings:limitations in the coloring scheme and a high probability of accepting an incorrect computation result.In this paper,we present an improved version of the XTH protocol,which revises the limitations of the original coloring scheme and further improves the verification ability.The analysis demonstrates that the resource expenditure is the same as for the XTH protocol,while the probability of accepting the wrong computation result is reduced from the original minimum(0.866)^(d*)to(0.819)^(d^(*)),where d;is the number of repeated executions of the protocol.
文摘We describe a scheme for universal quantum computation with Majorana fermions. We investigate two possible dissipative couplings of Majorana fermions to external systems, including metallic leads and local phonons. While the dissipation when coupling to metallic leads to uninteresting states for the Majorana fermions, we show that coupling the Majorana fermions to local phonons allows to generate arbitrary dissipations and therefore universal quantum operations on a single QuBit that can be enhanced by additional two-QuBit operations.
基金supported by the Key Research and Development Program of China(Grants No.2022YFA1404102,No.2022YFC3003802 and No.2021YFB3900204)the Research Project of Hubei Education Department(Grants No.B2023077)the Doctoral Scientific Research Foundation of Hubei University of Automotive Technology(Grants No.BK202432).
文摘Neutral atomic tweezer arrays have become a promising platform for quantum computation,which possess rich degrees of freedom(DoFs)as an important resource for encoding quantum information.We explore the DoF quantum resource in a ladder-shaped atomic tweezer array and propose a scheme of high-dimensional universal quantum computation.This scheme encodes qubits to two degrees of freedom of a single atom,namely the motional(Mo)and the site-occupation(SO)DoFs,which allows one atom to carry two qubits and results in a two-layer qubit architecture.The single-qubit rotational gates on Mo-and SO-qubits,as well as the intra-and inter-DoF Controlled-NOT(CNOT)gates are designed,and the crosstalk between qubits encoded with different DoFs is particularly addressed and compensated by the strategy composed of the detuning engineering and multi-chromatic Hamiltonian modulation.Quantum circuits are assembled from these gates in the ladder-shaped atomic array,generating the hyper and hyper-hybrid entangled states between the Mo and SO DoFs.Our work paves the way for high-dimensional quantum computation with multiple DoFs.
