Classical Control of Large-Scale Quantum Computers

Dr. Emily Roberts

The convergence of Very Large Scale Integration (VLSI) technology with quantum computing systems heralds a new era in computational capabilities. This article explores the evolving role of VLSI in facilitating scalable, reliable, and efficient quantum computing architectures. Key challenges such as integration of quantum bits (qubits) with classical control electronics, minimization of noise, and low-temperature operation constraints are discussed. The paper highlights emerging VLSI design methodologies tailored for quantum systems and presents future directions to realize hybrid quantum-classical chips. This integration promises breakthroughs in computational speed, energy efficiency, and system miniaturization essential for the next generation of computing technologies.

Urmila Mahadev

JuHwan Kim, Dongsik Jo

Recently, various researches and developments have been made to create a new computer that exceeds the capacity of a classical computer by utilizing a quantum computer. Quantum computing controls with operations of quantum bits called Qubit and uses various quantum physics phenomena to perform computations faster than classical computing. The quantum physics phenomena such as quantum entanglement and quantum superposition are used to carry out the computation. Although conventional classical computing systems can easily understand the current state of the system with pre-defined logic gates, symbols and procedures, on the other hand, the quantum computer have a complicated structure and difficult to intuitively understand. For example, when the number of controllable quantum bits hugely increases, complex quantum operations by quantum computing algorithms is generated. Also, to visualize large-scale complex quantum computer circuits, we need better ways to visualize quantum circuits. In this paper, in the process of designing a large-scale quantum computer system, the complex quantum algorithm and quantum system generated by controlling a large number of quantum bits are hierarchically visualized so that users can more effectively recognize the quantum computer system. In order to effectively design a computing circuit, we propose a quantum computing circuit visualization system using a hologram-like system.

Seth Lloyd

J. W. Clark, Dennis G. Lucarelli, Tzyh‐Jong Tarn

Jonas Helsen, Mark Steudtner, Menno Veldhorst +1 more

Abstract A central challenge for the scaling of quantum computing systems is the need to control all qubits in the system without a large overhead. A solution for this problem in classical computing comes in the form of so-called crossbar architectures. Recently we made a proposal for a large-scale quantum processor (Li et al arXiv:1711.03807 (2017)) to be implemented in silicon quantum dots. This system features a crossbar control architecture which limits parallel single-qubit control, but allows the scheme to overcome control scaling issues that form a major hurdle to large-scale quantum computing systems. In this work, we develop a language that makes it possible to easily map quantum circuits to crossbar systems, taking into account their architecture and control limitations. Using this language we show how to map well known quantum error correction codes such as the planar surface and color codes in this limited control setting with only a small overhead in time. We analyze the logical error behavior of this surface code mapping for estimated experimental parameters of the crossbar system and conclude that logical error suppression to a level useful for real quantum computation is feasible.