Continuous-time quantum walks (CTQWs) play a crucial role in quantumcomputing, especially for designing quantum algorithms. However, how to efficiently implement CTQWs is a challenging issue. In this paper, we study ...
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Continuous-time quantum walks (CTQWs) play a crucial role in quantumcomputing, especially for designing quantum algorithms. However, how to efficiently implement CTQWs is a challenging issue. In this paper, we study the implementation of CTQWs on sparse graphs, i.e., constructing efficient quantum circuits for implementing the unitary operator e−iHt, where H=γA (γ is a constant and A corresponds to the adjacency matrix of a graph). Our result is, for a d-sparse graph with N vertices and evolution time t, we can approximate e−iHt by a quantum circuit with gate complexity (d3∥H∥tNlog2(N))1+o(1), compared to the general Pauli decomposition, which scales like (∥H∥tN4log2(N))1+o(1). For sparse graphs, for instance, d=O(1), we obtain a noticeable improvement. Interestingly, our technique is related to graph decomposition. More specifically, we decompose the graph into a union of star graphs, and correspondingly, the Hamiltonian H can be represented as the sum of some Hamiltonians Hj, where each e−iHjt is a CTQW on a star graph which can be implemented efficiently.
The pursuit of quantum supremacy in computational tasks has driven the exploration of quantum algorithms capable of surpassing classical *** the realm of image processing,a notable advancement towards this objective i...
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The pursuit of quantum supremacy in computational tasks has driven the exploration of quantum algorithms capable of surpassing classical *** the realm of image processing,a notable advancement towards this objective is highlighted in the study by Cui et al.[1].Their work proposes a quantum image filtering(QImF)algorithm that exhibits exponential acceleration for a specific subset of images,offering a glimpse into the potential of quantumcomputing in image processing.
To reve al the non-Abelian braiding statistics of Major ana zero modes(MZMs),it is crucial to design a Majorana platform,in which MZMs can be easily manipulated in a broad topological nontrivial parameter *** is also ...
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To reve al the non-Abelian braiding statistics of Major ana zero modes(MZMs),it is crucial to design a Majorana platform,in which MZMs can be easily manipulated in a broad topological nontrivial parameter *** is also an essential step to confirm their *** this study,we propose an iron-based superconducting nanowire system with Majorana vortex states to satisfy desirable *** system has a radius-induced topological phase transition,giving a lower bound for the nanowire *** the topological phase,the iron-based superconducting nanowires have only one pair of MZMs over a wide range of radii,chemical potential and external magnetic *** wave function of MZMs has a sizable distribution at the side edge of the *** property enables the control of the interaction of MZMs in neighboring vortex nanowires and paves the way for Majorana fusion and braiding.
We demonstrate a digital electro-optic modulator (EOM) bias controller designed to maximize the extinction ratio of 100ps optical pulses, which are utilized for exciting single photons from quantum dots. The optical p...
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The preparation of quantum states is crucial for enabling quantum computations and *** this work,we present a general framework for preparing ground states of many-body systems by combining the measurement-feedback co...
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The preparation of quantum states is crucial for enabling quantum computations and *** this work,we present a general framework for preparing ground states of many-body systems by combining the measurement-feedback control process(MFCP)with machine learning ***,we employ Bayesian optimization(BO)to enhance the efficiency of determining the measurement and feedback operators within the *** an illustration,we study the ground state preparation of the one-dimensional Bose−Hubbard *** BO,we are able to identify optimal parameters that can effectively drive the system towards low-energy states with a high probability across various quantum *** results open up new directions for further exploration and development of advanced control strategies for quantum computations and simulations.
We propose linear and Kerr nonlinear compensators by continuous-variable photonic quantumcomputing for digital coherent transmission systems. The numerical simulation shows the possibility of compensators for chromat...
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We formulate a method to efficiently extract the non-classicality o f photon number measurements into optical traveling wave and show that practical logical qubits can be generated over 10% probability in a realistic ...
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ISBN:
(纸本)9798350369311
We formulate a method to efficiently extract the non-classicality o f photon number measurements into optical traveling wave and show that practical logical qubits can be generated over 10% probability in a realistic system.
In the digital era, data communication security is one of the main challenges. This research proposes a new method for secure image communication, which is a mixed triple logistic map and BB84 quantum key distribution...
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Laser locking is a crucial tool in various scientific applications, especially in the field of atomic physics, where the laser's frequency must be stable with respect to the frequencies of atomic transitions. This...
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The conditional displacement (CD) gate between an oscillator and a discrete-variable auxiliary qubit plays a key role in quantum information processing tasks, such as enabling universal control of the oscillator and l...
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The conditional displacement (CD) gate between an oscillator and a discrete-variable auxiliary qubit plays a key role in quantum information processing tasks, such as enabling universal control of the oscillator and longitudinal readout of the qubit; however, the gate is unprotected against the propagation of auxiliary qubit decay errors, meaning it is not fault tolerant. Here, we propose a CD gate scheme with fluxonium as the auxiliary qubit, which has been experimentally demonstrated to have a large noise bias and millisecond-level lifetimes. The proposed gate is applied cross-resonantly by modulating the external flux of the fluxonium at the frequency of the target oscillator, which requires minimal hardware overhead and does not increase sensitivity to decoherence mechanisms such as dephasing. We further provide a perturbative description of the gate mechanism and identify the error budget. Additionally, we develop an approximate procedure for choosing device and gate parameters that optimize gate performance. Following the procedure for multiple sets of fluxonium parameters from the literature, we numerically demonstrate CD gates with unitary fidelity exceeding 99.9% and gate times of hundreds of nanoseconds.
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