Quantum Conformal Prediction for Reliable Uncertainty Quantification in Quantum Machine Learning

Quantum machine learning is a promising programming paradigm for the optimization of quantum algorithms in the current era of noisy intermediate-scale quantum computers. A fundamental challenge in quantum machine learning is generalization, as the designer targets performance under testing conditions while having access only to limited training data. Existing generalization analyses, while identifying important general […]

MIMO Terahertz Quantum Key Distribution Under Restricted Eavesdropping

Quantum key distribution (QKD) can provide unconditional security to next-generation communication networks guaranteed by the laws of quantum physics. This article studies the secret key rate (SKR) of a continuous variable QKD (CV-QKD) system using multiple-input multiple-output (MIMO) transmission and operating at terahertz (THz) frequencies. Distinct from previous works, we consider a practical “restricted” eavesdropping […]

Perfect and Quasi-Perfect Codes for the Bosonic Classical-Quantum Channel

In this article, we explore perfect and quasi-perfect codes for the Bosonic channel, where information is generated by a laser and conveyed in the form of coherent states. In particular, we consider the phase-modulation codebook for coherent states in a Bosonic channel. We show that these phase-modulation codes are quasi-perfect as long as the cardinality […]

Fundamentals of Quantum Fourier Optics

All-quantum signal processing techniques are at the core of the successful advancement of most information-based quantum technologies. This article develops coherent and comprehensive methodologies and mathematical models to describe Fourier optical signal processing in full quantum terms for any input quantum state of light. We begin this article by introducing a spatially 2-D quantum state […]

On the Logical Error Rate of Sparse Quantum Codes

The quantum paradigm presents a phenomenon known as degeneracy that can potentially improve the performance of quantum error correcting codes. However, the effects of this mechanism are sometimes ignored when evaluating the performance of sparse quantum codes and the logical error rate is not always correctly reported. In this article, we discuss previously existing methods […]

A Feasible Quantum Sealed-Bid Auction Scheme Without an Auctioneer

In this article, we first define a primitive problem of secure multiparty computations, i.e., secure multiparty disjunction (SMD), and present a novel quantum protocol for SMD that can ensure information-theoretical security, i.e., unconditional security. Furthermore, based on the quantum SMD protocol, we design a quantum sealed-bid auction (QSA) scheme without an auctioneer. In the proposed […]

Discriminating Quantum States in the Presence of a Deutschian CTC: A Simulation Analysis

In an article published in 2009, Brun et al. proved that in the presence of a “Deutschian” closed timelike curve, one can map K distinct nonorthogonal states (hereafter, input set) to the standard orthonormal basis of a K -dimensional state space. To implement this result, the authors proposed a quantum circuit that includes, among SWAP gates, a fixed set […]

Hybrid Classical-Quantum Optimization Techniques for Solving Mixed-Integer Programming Problems in Production Scheduling

Quantum computing (QC) holds great promise to open up a new era of computing and has been receiving significant attention recently. To overcome the performance limitations of near-term QC, utilizing the current quantum computers to complement classical techniques for solving real-world problems is of utmost importance. In this article, we develop QC-based solution strategies that […]

Quantum Volume in Practice: What Users Can Expect From NISQ Devices

Quantum volume (QV) has become the de-facto standard benchmark to quantify the capability of noisy intermediate-scale quantum (NISQ) devices. While QV values are often reported by NISQ providers for their systems, we perform our own series of QV calculations on 24 NISQ devices currently offered by IBM Q, IonQ, Rigetti, Oxford Quantum Circuits, and Quantinuum […]

Simultaneous Estimation of Parameters and the State of an Optical Parametric Oscillator System

In this article, we consider the filtering problem of an optical parametric oscillator (OPO). The OPO pump power may fluctuate due to environmental disturbances, resulting in uncertainty in the system modeling. Thus, both the state and the unknown parameter may need to be estimated simultaneously. We formulate this problem using a state-space representation of the […]