We present a linear optics quantum computation scheme with a greatly reduced cost in resources compared to KLM. The scheme makes use of elements from cluster state computation and achieves comparable resource usage to those schemes while retaining the circuit based approach of KLM.
Correlation-Assisted Odd-Parity Encoded Gates in Coupled Fluxonium Qubits under Non-Markovian TLS Noise
School of Physics, Hangzhou Dianzi University(杭州电子科技大学物理学院);State Key Laboratory of Quantum Optics Technologies and Devices, Shanxi University(山西大学量子光学技术与器件国家重点实验室);Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation, Hangzhou Dianzi University(杭州电子科技大学量子态调控与光场操纵浙江省重点实验室)
Benchmarking simulation of hybrid decoding scheme for parity-encoded spin systems
NEC-AIST Quantum Technology Cooperative Research Laboratory(NEC-AIST量子技术联合研究实验室);National Institute of Advanced Industrial Science and Technology(国立产业技术综合研究所)
We propose a universal gate set for quantum computing with all-to-all connectivity and intrinsic robustness to bit-flip errors based on parity encoding. We show that logical controlled phase gate and $R_z$ rotations can be implemented in parity encoding with single-qubit operations. Together with logical $R_x$ rotations, implemented via nearest-neighbor controlled-NOT gates and an $R_x$ rotation, these form a universal gate set. As the controlled phase gate requires only single-qubit rotations, the proposed scheme has advantages for several cornerstone quantum algorithms, e.g., the quantum Fou…
One-step implementation of a multi-target-qubit controlled-phase gate with photonic qubits encoded via eigenstates of the photon-number parity operator
Lattice surgery protocols allow for the efficient implementation of universal gate sets with two-dimensional topological codes where qubits are constrained to interact with one another locally. In this work, we first introduce a decoder capable of correcting spacelike and timelike errors during lattice surgery protocols. Afterwards, we compute logical failure rates of a lattice surgery protocol for a biased circuit-level noise model. We then provide a new protocol for performing twist-free lattice surgery, where we avoid twist defects in the bulk of the lattice. Our twist-free protocol elimina…
Improving success probability in the LHZ parity embedding by computing with quantum walks
Institute for Theoretical Physics, University of Innsbruck(因斯布鲁克大学理论物理研究所);School of Computing, Newcastle University(纽卡斯尔大学计算机学院);Department of Physics, University of Strathclyde(斯特拉斯克莱德大学物理系);Parity Quantum Computing GmbH(Parity量子计算有限公司)
Practical hybrid decoding scheme for parity-encoded spin systems
NEC-AIST Quantum Technology Cooperative Research Laboratory(NEC-AIST量子技术联合研究实验室);National Institute of Advanced Industrial Science and Technology(产业技术综合研究所)
The coherent-state qubit is a promising candidate for optical quantum information processing due to its nearly-deterministic nature of the Bell-state measurement (BSM). However, its non-orthogonality incurs difficulties such as failure of the BSM. One may use a large amplitude ($α$) for the coherent state to minimize the failure probability, but the qubit then becomes more vulnerable to dephasing by photon loss. We propose a hardware-efficient concatenated BSM (CBSM) scheme with modified parity encoding using coherent states with reasonably small amplitudes ($|α| \lessapprox 2$), which simulta…
Quantum error correction is an indispensable ingredient for scalable quantum computing. In this Perspective we discuss a particular class of quantum codes called low-density parity-check (LDPC) quantum codes. The codes we discuss are alternatives to the surface code, which is the currently leading candidate to implement quantum fault-tolerance. We introduce the zoo of LDPC quantum codes and discuss their potential for making quantum computers robust against noise. In particular, we explain recent advances in the theory of LDPC quantum codes related to certain product constructions and discuss …