Quantum Computers and Their Software Interfaces.

Yuichiro Minato

Robert Wille, L. Schmid, Yannick Stade +4 more

Quantum computing is a promising technology that requires a sophisticated software stack to connect end users to the wide range of possible quantum backends. However, current software tools are usually hard-coded for single platforms and lack a dynamic interface that can automatically retrieve and adapt to changing physical characteristics and constraints of different platforms. With new hardware platforms frequently introduced and their performance changing on a daily basis, this constitutes a serious limitation. In this paper, we show-case a concept and a prototypical realization of an interface, called the Quantum Device Management Interface (QDMI), that addresses this problem by explicitly connecting the software and hardware developers, mediating between their competing interests. QDMI allows hardware platforms to provide their physical characteristics in a standardized way, and software tools to query that data to guide the compilation process accordingly. This enables software tools to automatically adapt to different platforms and to optimize the compilation process for the specific hardware constraints. QDMI is a central part of the Munich Quantum Software Stack (MQSS)-a sophisticated software stack to connect end users to the wide range of possible quantum backends. QDMI is publicly available as open source at https://github.com/Munich-Quantum-Software-Stack/QDMI.

JARROD MCCLEAN, Thomas Häner, Damian S. Steiger +1 more

FermiLib is an open source software package designed to facilitate the development and testing of algorithms for simulations of fermionic systems on quantum computers. Fermionic simulations represent an important application of early quantum devices with a lot of potential high value targets, such as quantum chemistry for the development of new catalysts. This software strives to provide a link between the required domain expertise in specific fermionic applications and quantum computing to enable more users to directly interface with, and develop for, these applications. It is an extensible Python library designed to interface with the high performance quantum simulator, ProjectQ, as well as application specific software such as PSI4 from the domain of quantum chemistry. Such software is key to enabling effective user facilities in quantum computation research.

Rong-Yang Sun, Tomonori Shirakawa, Hidehiko Kohshiro +2 more

Tensor networks (TNs) are a central computational tool in quantum science and artificial intelligence. However, the lack of a unified software interface across tensor-computing frameworks severely limits the portability of TN applications, coupling algorithmic development to specific hardware and software back ends. To address this challenge, we introduce the Tensor Computing Application Programming Interface (TCAPI)---an application-oriented, lightweight API designed to enable framework-independent, high-performance TN applications, currently specified for \texttt{C++} and \texttt{Python}. TCAPI provides well-defined type-system conventions that abstract tensor objects, together with a minimal yet expressive set of core functions for essential tensor manipulations and tensor linear-algebra operations, with operation semantics shared across language specifications. Through numerical demonstrations of representative tensor-network applications implemented in \texttt{C++} using TCAPI, we show that code written against TCAPI can be migrated seamlessly across heterogeneous hardware and software platforms while achieving performance comparable to native framework implementations. We further provide open-source implementations of TCAPI based on \textit{Cytnx} and \textit{ITensor} in \texttt{C++}, and on \textit{NumPy} in \texttt{Python}, demonstrating its practicality and ease of integration with existing tensor-computing frameworks.

T. R. Govindan

Ercüment Kaya, Muhammad Nufail Farooqi, Minh Chung +3 more

Quantum Computing (QC) is an emerging technology that requires customized tools, such as software stacks and programming interfaces. However, currently, the tools are generally tightly coupled and exhibit limited interoperability. This, in particular, affects High Performance Computing (HPC) facilities and data centers, which are required to support multiple programming interfaces. In this paper, we introduce MQSS Client, a unifying, context-aware access layer and programming library that decouples the programming interfaces and the underlying compilation and runtime stack. MQSS Client aims to support all existing programming interfaces by providing abstractions for resources, jobs, and results. It provides two access modes to accommodate the varied needs of remote and HPC users. Thus, interoperability between software stacks and programming interfaces increases.