Welcome to the Quantum Realm. 

Enjoy today’s breakdown of news, research, & events within quantum.

🕰️ 📖 Tiqker clock gets its UK Debut. Plus, so much new research — plenty of dense reading material for the weekend. Surely, just what you were looking for on a Friday night. Don’t worry, I’ve got you.

🗓️ UPCOMING

Sunday, June 30 | QTM-X Quantum Education Series 5 of 10 Quantum Hardware

Monday, July 1 | TQN Quantum Safe Transition Working Group

📰 NEWS QUICK BYTES

🕰️ Infleqtion milestone with first UK sale of Tiqker quantum clock: Infleqtion has announced its first UK commercial sale of the Tiqker optical atomic clock to the University of Strathclyde. The Tiqker will be integrated into Professor Erling Riis’s lab for precision timekeeping and navigation research to advance positioning, navigation, and timing technology as supported by the National Physical Laboratory’s National Timing Centre. This goes hand in hand with the UK’s efforts to develop resilient timing infrastructure and reduce dependency on global navigation satellite systems.

🤔 Something was missing in last night’s US presidential debate: The first presidential debate for the 2024 U.S. election left a notable gap by not addressing future technological challenges related to artificial intelligence and quantum computing despite their increasing relevance in policy and national security. The next president will need to be ready to confront cybersecurity risk in terms of quantum encryption-breaking technologies. As AI and quantum computing continue to advance, their impact on various sectors and national security cannot be ignored.

🖥️ Equal1 Labs prepares to launch UnityQ quantum chip: Equal1 Labs is set to debut its UnityQ quantum computing chip in 2025, combining six electron-spin based qubits with ARM CPUs, NPUs, and AI acceleration. CEO Jason Lynch emphasizes the integration of quantum computing with the existing semiconductor ecosystem. The company, founded in 2017, has raised $30 million and is testing its technology on standard foundry processes like silicon-germanium and Globalfoundries' 22FDX. Equal1 envisions a diverse quantum computing landscape with various technologies coexisting to address different needs.

🔬 UCPH and MIT launch transatlantic quantum computing collaboration: The University of Copenhagen and MIT have announced a four-year collaboration to accelerate advancements in quantum computing, especially in terms of developing fault-tolerant quantum computers. Funded by the Novo Nordisk Foundation Quantum Computing Programme, this partnership will establish identical quantum labs at both institutions for continuous collaboration and innovation. The focus will primarily be on addressing some of the most challenging quantum puzzles by leveraging the combined strengths of both research teams.

🔒 Canada implements stricter export controls on quantum technologies: Canada recently announced amendments to the Export Control List, effective July 20, 2024. The updates include requiring individual permits for exporting specific quantum computing and advanced semiconductor technologies, excluding exports to the United States. The new controls include quantum computers with 34+ qubits, CryoCMOS integrated circuits, technology for GAAFET structures, equipment for etching these structures, and advanced SEM equipment. The goal behind the amendments is to prevent the proliferation of strategic technologies to hostile entities and align Canada’s regulations with similar measures in the UK, France, Spain, and Finland.

☕️ FRESHLY BREWED RESEARCH

JuliVQC: an Efficient Variational Quantum Circuit Simulator for Near-Term Quantum Algorithms: JuliVQC is a highly efficient variational quantum circuit simulator designed to support near-term quantum algorithms. By leaning on the high-performance Julia scripting language, JuliVQC emphasizes transparency, cache-friendly implementation, and native automatic differentiation, which makes it superior in simulating both noiseless and noisy quantum circuits. Breakdown here.

Twin-Field Quantum Key Distribution with Local Frequency Reference: A practical and simplified method for implementing twin-field quantum key distribution is introduced using frequency-stabilized lasers referenced to acetylene absorption spectroscopy and eliminating the need for complex frequency locking mechanisms. TFQKD is successfully demonstrated over distances of up to 502 km with high secure key rates and low error rates, making it a cost-effective solution for long-distance quantum communication networks. Breakdown here.

QOS: A Quantum Operating System: The Quantum Operating System provides a unified system stack for managing quantum resources and optimizing quantum applications. QOS includes a modular compiler for optimizing quantum programs and a runtime system for efficient resource management, enhancing performance on small and noisy quantum devices. Evaluations on IBM's quantum devices demonstrate significant improvements in execution quality and reduced waiting times.

ML-Powered FPGA-based Real-Time Quantum State Discrimination Enabling Mid-circuit Measurements: QubiCML is an FPGA-based system for real-time qubit state discrimination enabling mid-circuit measurements. QubiCML uses a multi-layer neural network to ensure low-latency and high-accuracy state discrimination. It achieves an average accuracy of 98.5% with just a 500ns shot on superconducting quantum processors. The system significantly improves qubit state identification.

Resource overheads and attainable rates for trapped-ion lattice surgery: This is an analysis on the resource overheads and attainable rates for implementing fault-tolerant lattice surgery in modular trapped-ion quantum computers. It estimates the number of ions required and the achievable rates of lattice surgery under different cycle time and highlights the resource demands due to the slow inter-module coupling rates. There is a need for improved optical coupling to enhance scalability and efficiency in trapped-ion quantum computing systems.

Solving the homogeneous Bethe-Salpeter equation with a quantum annealer: A D-Wave quantum annealer is used to solve the homogeneous Bethe-Salpeter equation for a relativistic bound system in a quantum field theory framework. By transforming the hBSE into a generalized eigenvalue problem, quantum annealing can handle non-symmetric matrices and achieve results comparable to classical algorithms while maintaining scalability for larger matrices.

Enhancing Cyber Security Using Quantum Computing and Artificial Intelligence: A Review: The combined potential of quantum computing and artificial intelligence are reviewed for cybersecurity. Traditional encryption methods are limited against quantum attacks and the need for quantum-resistant encryption algorithms is well-known. The review explores the integration of quantum computing for advanced threat detection and mitigation while emphasizing the development of quantum-enhanced security protocols, such as quantum random number generators and quantum secure communication. The article also considers the ethical and regulatory implications of implementing quantum cybersecurity solutions.

CDQKL: Consensus-based Distributed Quantum Kernel Learning: CDQKL is a consensus-based distributed quantum kernel learning approach designed to improve the efficiency and accuracy of quantum kernel learning without sharing local training data. By exchanging model parameter information between adjacent nodes, CDQKL accelerates the training process and improves upon classification performance, as demonstrated through experiments on artificial and real-world datasets. This approach shows promise for privacy-preserving machine learning tasks in future distributed quantum computing scenarios.

UNTIL SUNDAY.

BREAKDOWN

JuliVQC: an Efficient Variational Quantum Circuit Simulator for Near-Term Quantum Algorithms

🔍️ SIGNIFICANCE: 

• JuliVQC is a variational quantum circuit simulator designed for near-term quantum algorithms, specifically targeting the classical simulation of the Zuchongzhi quantum processors. This addresses the critical challenge of both characterizing and optimizing quantum circuits in NISQ era. By offering a highly efficient and transparent simulation tool, JuliVQC supports researchers in exploring heuristic quantum algorithms, benchmarking performance, and optimizing gate parameters without relying on actual quantum hardware.

• This differentiation from previous methods lies in its focus on efficiency, cache-friendly implementation, and native support for automatic differentiation, which sets it apart from other simulators like ProjectQ, Cirq, and Qiskit, which may not optimize for the same level of performance in these specific aspects.

🧪 METHODOLOGY: 

• Developing JuliVQC meant using the high-performance Julia scripting language while emphasizing three design principles: transparency, efficiency, and support for automatic differentiation.

• JuliVQC uses a cache-friendly approach for elementary gate operations which improves computational efficiency by maximizing the use of CPU cache and supporting shared-memory parallelization.

• It provides functions to initialize quantum states as state vectors or density matrices, allowing for both pure and mixed states to be efficiently handled.

• The simulator includes a wide range of predefined quantum gates and channels with special optimizations for frequently used gates to ensure higher performance. It also supports parametric gates necessary for variational circuits.

• It integrates classical automatic differentiation techniques for both noiseless and noisy quantum circuits to minimize memory usage and computational cost during gradient calculations.

• Extensive use of shared-memory parallelization allows the simulator to efficiently handle operations on large quantum states, with performance scaling almost linearly with the number of threads used.

📊 OUTCOMES & OUTLOOK: 

• JuliVQC was shown to perform exceptionally well across different benchmark scenarios and often outperformed other popular simulators in tasks such as simulating quantum circuits and variational quantum circuits. Specifically, JuliVQC had superior performance in executing Hadamard, Pauli-X rotation, and CNOT gates, and excelled in simulating random quantum circuits, especially for larger circuits.

• JuliVQC’s performance in simulating noisy quantum circuits is comparable to the noiseless counterparts which indicates it should be sufficiently suited to handling real-world quantum computing situations.

BREAKDOWN

Twin-Field Quantum Key Distribution with Local Frequency Reference

🔍️ SIGNIFICANCE: 

• Twin-field quantum key distribution is a promising technique in quantum communication in that it has a higher secure key rate over long distances and overcomes the linear rate-loss limit that has been a significant barrier. One of the major hurdles in the implementation of TFQKD is the elimination of frequency differences between independent laser sources. This method proposes to overcome this barrier by leaning on a more straightforward and practical approach using frequency-stabilized lasers referenced to the saturated absorption spectroscopy of acetylene which eliminates the need for complex frequency locking mechanisms.

🧪 METHODOLOGY: 

• Frequency-stabilized lasers with acetylene absorption spectroscopy were used as an absolute reference to maintain the coherence of the twin light fields necessary for TFQKD.

• A 4-intensity sending-or-not-sending TFQKD protocol was implemented over 502, 301, and 201 km of ultralow-loss optical fiber.

• A narrow linewidth continuous wave light beam was modulated to generate a waveform pattern where single-photon-level quantum signal pulses were time-multiplexed with strong phase reference pulses.

• Superconducting nanowire single-photon detectors and a time tagger were used to detect and record the interference results.

📊 OUTCOMES & OUTLOOK: 

• TFQKD was successful over all three lengths of ultralow-loss optical fiber with a high-performance single-photon interference with a low phase flip error rate of less than 3%.

• It was validated to be less complex and more cost-effective compared to previous methods that utilized ultrastable lasers and electro-optic frequency combs or high-count measurement devices.

• Overall, this approach simplifies the system, reduces costs, and improves scalability to makeTFQKD more accessible and practical for widespread use, even in environments with limited channel resources and variable conditions.