Noise Robustness of Quantum Relaxation for Combinatorial Optimization
Relaxation is a common way for dealing with combinatorial optimization problems.
Optimizing the Electrical Interface for Large-Scale Color-Center Quantum Processors
Quantum processors based on color centers in diamond are promising candidates for future large-scale quantum computers thanks to their flexible optical interface, (relatively) high operating temperature, and high-fidelity operation. Similar to other quantum computing platforms, the electrical interface required to control and read out such qubits may limit both the performance of the whole system […]
Spatiotemporal Multiplexed Rydberg Receiver
Rydberg states of alkali atoms, where the outer valence electron is excited to high principal quantum numbers, have large electric dipole moments allowing them to be used as sensitive, wideband, electric field sensors. These sensors use electromagnetically induced transparency (EIT) to measure incident electric fields. The characteristic timescale necessary to establish EIT determines the effective […]
A Modular Quantum Compilation Framework for Distributed Quantum Computing
For most practical applications, quantum algorithms require large resources in terms of qubit number, much larger than those available with current noisy intermediate-scale quantum processors. With the network and communication functionalities provided by the quantum Internet, distributed quantum computing (DQC) is considered as a scalable approach for increasing the number of available qubits for computational […]
Versatile and Concurrent FPGA-Based Architecture for Practical Quantum Communication Systems
This article presents a hardware and software architecture, which can be used in those systems that implement practical quantum key distribution (QKD) and quantum random-number generation (QRNG) schemes. This architecture fully exploits the capability of a System on a Chip (SoC), which comprehends both a field-programmable gate array (FPGA) and a dual-core CPU unit. By […]
Quantum Circuit Architecture Optimization for Variational Quantum Eigensolver via Monto Carlo Tree Search
The advent of noisy intermediate-scale quantum (NISQ) devices provide crucial promise for the development of quantum algorithms. Variational quantum algorithms have emerged as one of the best hopes to utilize NISQ devices. Among these is the famous variational quantum eigensolver (VQE), where one trains a parameterized and fixed quantum circuit (or an ansatz) to accomplish […]
QubiC: An Open-Source FPGA-Based Control and Measurement System for Superconducting Quantum Information Processors
As quantum information processors grow in quantum bit (qubit) count and functionality, the control and measurement system becomes a limiting factor to large-scale extensibility. To tackle this challenge and keep pace with rapidly evolving classical control requirements, full control stack access is essential to system-level optimization. We design a modular field-programmable gate array (FPGA)-based system […]
Experimental Demonstrations of Native Implementation of Boolean Logic Hamiltonian in a Superconducting Quantum Annealer
Experimental demonstrations of quantum annealing with “native” implementation of Boolean logic Hamiltonians are reported. As a superconducting integrated circuit, a problem Hamiltonian whose set of ground states is consistent with a given truth table is implemented for quantum annealing with no redundant qubits. As examples of the truth table, nand and nor are successfully fabricated […]
Performance of Domain-Wall Encoding for Quantum Annealing
In this article, we experimentally test the performance of the recently proposed domain-wall encoding of discrete variables Chancellor, 2019, on Ising model flux qubit quantum annealers. We compare this encoding with the traditional one-hot methods and find that they outperform the one-hot encoding for three different problems at different sizes of both the problem and […]
Reducing the Depth of Linear Reversible Quantum Circuits
In quantum computing the decoherence time of the qubits determines the computation time available, and this time is very limited when using current hardware. In this article, we minimize the execution time (the depth) for a class of circuits referred to as linear reversible circuits, which has many applications in quantum computing (e.g., stabilizer circuits, […]