Mode-Manipulated Multimode Cavity for Quantum Memory

In this article, a quasi-elliptical geometry and the iris technique are applied to a multimode cavity to manipulate the resonant mode in the desired direction for quantum memories. By applying quasi-elliptical geometry, the characteristics of monotonically increasing, equally spaced, and monotonically decreasing frequency intervals between the modes are realized. To manipulate a certain mode, an […]

The Optimization and Application of 3-Bit Hermitian Gates and Multiple Control Toffoli Gates

The well-known 3-bit Hermitian gate (a Toffoli gate) has been implemented using Clifford+T circuits. Compared with the Peres gate, its implementation circuit requires more controlled- not (cnot) gates. However, the Peres gate is not Hermitian. This article reports four 3-bit Hermitian gates named LI gates, whose realized circuits have the same T-count, T-depth, and cnot […]

Machine-Learning-Based Parameter Estimation of Gaussian Quantum States

In this article, we propose a machine-learning framework for parameter estimation of single-mode Gaussian quantum states. Under a Bayesian framework, our approach estimates parameters of suitable prior distributions from measured data. For phase-space displacement and squeezing parameter estimation, this is achieved by introducing expectation–maximization (EM)-based algorithms, while for phase parameter estimation, an empirical Bayes method […]

DQRA: Deep Quantum Routing Agent for Entanglement Routing in Quantum Networks

Quantum routing plays a key role in the development of the next-generation network system. In particular, an entangled routing path can be constructed with the help of quantum entanglement and swapping among particles (e.g., photons) associated with nodes in the network. From another side of computing, machine learning has achieved numerous breakthrough successes in various […]

Estimation of the CHSH Parameter Using HOM Interference

The Clauser–Horne–Shimony–Holt (CHSH) experiment is an essential test of nonlocality in quantum mechanics and can be used to validate the principle of entanglement. In addition to verifying entanglement, the measurable CHSH parameter can also be used to gauge the quality of the entanglement present in a system. The measurement of Hong–Ou–Mandel (HOM) interference is another […]

Long-Term Secure Distributed Storage Using Quantum Key Distribution Network With Third-Party Verification

The quantum key distribution (QKD) network with Vernam’s one-time pad encryption and secret sharing are powerful security tools to realize an information theoretically secure (ITS) distributed storage system. In the work of Fujiwara et al., a single-password-authenticated secret sharing (SPSS) scheme based on the QKD network and Shamirs secret sharing was experimentally demonstrated; it confirmed ITS […]

Efficient Quantum Network Communication Using Optimized Entanglement Swapping Trees

Quantum network communication is challenging, as the no-cloning theorem in the quantum regime makes many classical techniques inapplicable; in particular, the direct transmission of qubit states over long distances is infeasible due to unrecoverable errors. For the long-distance communication of unknown quantum states, the only viable communication approach (assuming local operations and classical communications) is […]

A Connection-Oriented Entanglement Distribution Design in Quantum Networks

Quantum networks create a completely new way for communication, and the most important function of a quantum network is to generate long-distance quantum entanglement to serve a number of quantum applications. As the scale of the network expands, in order to establish end-to-end entanglement between two remote nodes, entangled pairs need to be generated and […]

Decentralization Using Quantum Blockchain: A Theoretical Analysis

Blockchain technology has been prominent recently due to its applications in cryptocurrency. Numerous decentralized blockchain applications have been possible due to blockchains’ nature of distributed, secured, and peer-to-peer storage. One of its technical pillars is using public-key cryptography and hash functions, which promise a secure, pseudoanonymous, and distributed storage with nonrepudiation. This security is believed […]

High-Stability Cryogenic System for Quantum Computing With Compact Packaged Ion Traps

Cryogenic environments benefit ion trapping experiments by offering lower motional heating rates, collision energies, and an ultrahigh vacuum (UHV) environment for maintaining long ion chains for extended periods of time. Mechanical vibrations caused by compressors in closed-cycle cryostats can introduce relative motion between the ion and the wavefronts of lasers used to manipulate the ions. […]