MIT’s Quantum Programming Language ‘Twist’ Aims to Redefine Tech

MIT's quantum programming language enables taking a step towards advancement in quantum computing

After decades of heavy work with no promise of success, quantum computing is suddenly buzzing with almost feverish excitement and activity. Experts believe that the future might witness impending quantum supremacy, the moment when a quantum computer can carry out a task beyond the means of modern classical supercomputers. The whole point of quantum computing is that a quantum bit counts for much more than a classical bit. There are both merits and challenges involved in quantum computing. But the developments in this sector prove that researchers and scientists are quite determined to eradicate all technical complexities and establish quantum computing as the future of advanced computing. The quantum race is already underway, as governments and private investors from all around the world are pouring billions of dollars into quantum research. MIT's quantum programming language 'Twist' is one such innovation that is aimed to identify the problems and work towards making developers competent enough to create quantum programs with few errors. 

Programming quantum computers require awareness of something called 'entanglement', a computational multiplier for qubits of sorts which translates to a lot of power. While programming, if in case one qubit is discarded without the knowledge of its entanglement with another qubit, it can destroy the data stored in the other qubit. Therefore, it could jeopardize the correctness of this program. 

Introducing 'Twist'

Twist is a programming language created by top scientists from MIT's Computer Science and Artificial Intelligence for quantum computing, This programming language is designed in such a way that it can describe and verify which pieces of data are entangled in a quantum program. The language uses purity, a concept that surfaces mostly in the absence of entanglement and results in more intuitive programs with lesser bugs. 

One of the language's features is a type system that enables developers to specify which expressions and pieces of data within their programs are pure. According to Charles Yuan, a Ph.D., student in computer science at MIT CSAIL and lead author on the paper about Twist mentions that a pure piece of data is free from possible bugs and unintuitive effects caused by entanglement. Twist also has purity assertion operations to confirm that an expression lacks entanglement with any other piece of data, as well as static analyses and run-time checks to verify these assertions. 

The team also introduced small bugs to some of the programs and found that Twist can detect those bugs and reject the wrong programs. While several researchers are focused on building efficient and optimized quantum hardware, Twist aims to bridge the gap in quantum software. 

While the quantum field is still a little flashy and futuristic, with visions of ivory gold coming to mind, quantum computers have the potential for computation breakthroughs in classical, complex problems. One of the primary challenges in computational sciences is dealing with the complexity of the problem and the amount of computation that is actually needed. But scientists at MIT designed the program to be expressive enough to write out programs for well-known quantum algorithms and identify bugs in their implementations. They modified the programs to introduce some kind of bug that would be relatively easier for a human programmer to detect and showed that Twist could manually identify the bugs and reject the programs. 

The crucial next step for using Twist is to create other higher-level quantum programming languages, Most quantum programming languages today still resemble assembly language, binding low-level operations, without mindfulness towards things like data types and functions. This is quite typical in classical software engineering. The team is already building upon Twist, another programming language, to tackle other quantum phenomena such as phase and superposition, but they hope Twist will pave the way for creating better quantum programs. More such innovations in the quantum domain, enabling the rapid advancement of the technology.