Coming Over the Horizon
Quantum Communication Enters the Mainstream
Communication is the connective tissue of society, weaving individuals into groups and communities and mediating the progress and development of culture. The technology of communications evolves continuously, occasionally undergoing paradigm shifts such as those brought about by the Gutenberg press and broadcast television.
From historical examples such as the proliferation of fast merchant trading ships, to the modern telecommunications networks spread across the world via a web of cables buried under the sea floor and satellites thousands of kilometres high, the need for better communication infrastructure has driven some of our most ambitious technologies to date.
Today, emerging quantum technologies are poised to revolutionise the field of communication once again. They promise new and incredibly valuable opportunities for dependable and secure communications between people, communities, companies, and governments everywhere. Our ability to understand and control quantum systems has opened a new world of exciting possibilities. Soon we might build long-distance quantum communication links and networks, eventually leading to what is known as the quantum internet.
While some embryonic quantum communication systems are already in place, realisation of their full potential will require significant technological advances. With engineering teams around the world working at pace to deliver this promise across industrial sectors, the need to invest in expert knowledge is rising.
NASA has been a pioneer in space-based communication over many decades, and more recently has emerged as a leader in space-based quantum communication, dedicating new resources for scientists, engineers and communication systems experts to learn about the field.
Recently, NASA’s Space Communications and Navigation (SCaN) program commissioned a booklet titled Quantum Communication 101, authored by several of our team at Quantinuum. This will be a go-to resource for the global community of scientists and experts that NASA supports, but importantly it has been written so that it requires almost no prior technical knowledge while providing a rigorous account of the emerging field of quantum communications.
What follows is a taster of what’s in Quantum Communication 101.
What is quantum communication?
For the words I am typing now to reach your computer screen, I need to rely on modern communication networks. My laptop memory, Wi-Fi router and communication channels rely on the physics of things like transistors, currents, and radio waves which obey the more familiar, “classical" laws of physics.
The field of quantum communication, however, relies on the counterintuitive rules of quantum physics. Thanks to incredible feats of engineering, in place of continuous beams of light from diodes, we can now control individual photons to send and receive quantum information. By taking advantage of the peculiar quantum phenomena that they exhibit, like superposition and entanglement, new possibilities are emerging which were previously unimaginable.
Cutting-edge applications
In the growing landscape of potential applications in quantum communication, cybersecurity is already deeply rooted. At Quantinuum, for example, quantum computers are used to generate randomness, the fundamental building block of secure encryption. Elsewhere, prototype quantum networks for secure communications already span metropolitan areas.
As our techniques in quantum communication advance, we may unlock new possibilities in quantum computing, which promises to solve problems too difficult even for supercomputers, and quantum metrology, which will enable measurements at an unprecedented precision. Quantum states of light have already been used in LIGO - a large-scale experiment operated by CalTech and MIT to detect ripples in the fabric of space-time itself.
Connecting the dots: towards a quantum internet
The end goal of quantum communication is what many refer to as the quantum internet, through which we will seamlessly send quantum signals across many quantum networks. This will be an enormous engineering challenge, requiring international collaboration and the evolution of our existing infrastructure.
Although the exact form that this network will take is yet unknown, we can say with confidence that it will need to pass through space. Much like satellites help to globally connect the Internet, the launch of quantum-capable satellites will play a vital role in a global quantum internet.
Building a quantum ecosystem
The path to a quantum internet will depend on growing a diverse and expert workforce. This is well understood by bodies such as the National Science Foundation who recently announced a $5.1M Center for Quantum Networks aimed at architecting the quantum internet. Over the last few years, we have seen growing investment worldwide, such as the $1.1B Quantum Technology Flagship in Europe and the $11B Chinese National Laboratory for Quantum Information Science. Important industrial investments are being made by large corporations such as IBM, Google, Intel, Honeywell, Cisco, Amazon, and Microsoft.
Amongst this surge in interest, NASA’s SCaN program has proposed a series of mission concepts for building and testing infrastructure for space-based quantum communication. These include launching satellites capable of sending and receiving quantum signals between ground stations and eventually other satellites. These quantum signals may be entangled photons – a feature that will play an extremely important role in future networks. One such mission concept is shown below, where a quantum-capable satellite with a source of entangled photons connects an intercontinental quantum network.
The second quantum revolution is at an exciting precipice where our ability to transmit quantum information, both on Earth and in space, will be pivotal. Whilst our evolving quantum technologies already show a great deal of promise, it is perhaps the ground-breaking applications that we are yet to discover which will ultimately determine our success.
It is more important than ever that we support education and collaboration in advancing quantum technologies. Quantum Communication 101 aims to be a starting point for a general audience looking to learn about the topic for the first time, as well as those who wish to explore in detail the technologies that will make the first quantum networks a reality.
If you would like to better understand the exciting prospects of quantum communication, you can find the Quantum Communication 101 booklet on the NASA SCaN website.
About Quantinuum
Quantinuum, the world’s largest integrated quantum company, pioneers powerful quantum computers and advanced software solutions. Quantinuum’s technology drives breakthroughs in materials discovery, cybersecurity, and next-gen quantum AI. With over 500 employees, including 370+ scientists and engineers, Quantinuum leads the quantum computing revolution across continents.
At this year’s Q2B Silicon Valley conference from December 10th – 12th in Santa Clara, California, the Quantinuum team will be participating in plenary and case study sessions to showcase our quantum computing technologies.
Schedule a meeting with us at Q2B
Meet our team at Booth #G9 to discover how Quantinuum is charting the path to universal, fully fault-tolerant quantum computing.
Join our sessions:
Tuesday, Dec 10, 10:00 - 10:20am PT
Plenary: Advancements in Fault-Tolerant Quantum Computation: Demonstrations and Results
There is industry-wide consensus on the need for fault-tolerant QPU’s, but demonstrations of these abilities are less common. In this talk, Dr. Hayes will review Quantinuum’s long list of meaningful demonstrations in fault-tolerance, including real-time error correction, a variety of codes from the surface code to exotic qLDPC codes, logical benchmarking, beyond break-even behavior on multiple codes and circuit families.
Wednesday, Dec 11, 4:30 – 4:50pm PT
Keynote: Quantum Tokens: Securing Digital Assets with Quantum Physics
Mitsui’s Deputy General Manager, Quantum Innovation Dept., Corporate Development Div., Koji Naniwada, and Quantinuum’s Head of Cybersecurity, Duncan Jones will deliver a keynote presentation on a case study for quantum in cybersecurity. Together, our organizations demonstrated the first implementation of quantum tokens over a commercial QKD network. Quantum tokens enable three previously incompatible properties: unforgeability guaranteed by physics, fast settlement without centralized validation, and user privacy until redemption. We present results from our successful Tokyo trial using NEC's QKD commercial hardware and discuss potential applications in financial services.
Wednesday, Dec 11, 5:10 – 6:10pm PT
Quantinuum and Mitsui Sponsored Happy Hour
Join the Quantinuum and Mitsui teams in the expo hall for a networking happy hour.
Particle accelerator projects like the Large Hadron Collider (LHC) don’t just smash particles - they also power the invention of some of the world’s most impactful technologies. A favorite example is the world wide web, which was developed for particle physics experiments at CERN.
Tech designed to unlock the mysteries of the universe has brutally exacting requirements – and it is this boundary pushing, plus billion-dollar budgets, that has led to so much innovation.
For example, X-rays are used in accelerators to measure the chemical composition of the accelerator products and to monitor radiation. The understanding developed to create those technologies was then applied to help us build better CT scanners, reducing the x-ray dosage while improving the image quality.
Stories like this are common in accelerator physics, or High Energy Physics (HEP). Scientists and engineers working in HEP have been early adopters and/or key drivers of innovations in advanced cancer treatments (using proton beams), machine learning techniques, robots, new materials, cryogenics, data handling and analysis, and more.
A key strand of HEP research aims to make accelerators simpler and cheaper. A key piece of infrastructure that could be improved is their computing environments.
CERN itself has said: “CERN is one of the most highly demanding computing environments in the research world... From software development, to data processing and storage, networks, support for the LHC and non-LHC experimental programme, automation and controls, as well as services for the accelerator complex and for the whole laboratory and its users, computing is at the heart of CERN’s infrastructure.”
With annual data generated by accelerators in excess of exabytes (a billion gigabytes), tens of millions of lines of code written to support the experiments, and incredibly demanding hardware requirements, it’s no surprise that the HEP community is interested in quantum computing, which offers real solutions to some of their hardest problems.
As the authors of this paper stated: “[Quantum Computing] encompasses several defining characteristics that are of particular interest to experimental HEP: the potential for quantum speed-up in processing time, sensitivity to sources of correlations in data, and increased expressivity of quantum systems... Experiments running on high-luminosity accelerators need faster algorithms; identification and reconstruction algorithms need to capture correlations in signals; simulation and inference tools need to express and calculate functions that are classically intractable.”
The HEP community’s interest in quantum computing is growing. In recent years, their scientists have been looking carefully at how quantum computing could help them, publishing a number of papers discussing the challenges and requirements for quantum technology to make a dent (here’s one example, and here’s the arXiv version).
In the past few months, what was previously theoretical is becoming a reality. Several groups published results using quantum machines to tackle something called “Lattice Gauge Theory”, which is a type of math used to describe a broad range of phenomena in HEP (and beyond). Two papers came from academic groups using quantum simulators, one using trapped ions and one using neutral atoms. Another group, including scientists from Google, tackled Lattice Gauge Theory using a superconducting quantum computer. Taken together, these papers indicate a growing interest in using quantum computing for High Energy Physics, beyond simple one-dimensional systems which are more easily accessible with classical methods such as tensor networks.
We have been working with DESY, one of the world’s leading accelerator centers, to help make quantum computing useful for their work. DESY, short for Deutsches Elektronen-Synchrotron, is a national research center that operates, develops, and constructs particle accelerators, and is part of the worldwide computer network used to store and analyze the enormous flood of data that is produced by the LHC in Geneva.
Our first publication from this partnership describes a quantum machine learning technique for untangling data from the LHC, finding that in some cases the quantum approach was indeed superior to the classical approach. More recently, we used Quantinuum System Model H1 to tackle Lattice Gauge Theory (LGT), as it’s a favorite contender for quantum advantage in HEP.
Lattice Gauge Theories are one approach to solving what are more broadly referred to as “quantum many-body problems”. Quantum many-body problems lie at the border of our knowledge in many different fields, such as the electronic structure problem which impacts chemistry and pharmaceuticals, or the quest for understanding and engineering new material properties such as light harvesting materials; to basic research such as high energy physics, which aims to understand the fundamental constituents of the universe, or condensed matter physics where our understanding of things like high-temperature superconductivity is still incomplete.
The difficulty in solving problems like this – analytically or computationally – is that the problem complexity grows exponentially with the size of the system. For example, there are 36 possible configurations of two six-faced dice (1 and 1 or 1 and 2 or 1and 3... etc), while for ten dice there are more than sixty million configurations.
Quantum computing may be very well-suited to tackling problems like this, due to a quantum processor’s similar information density scaling – with the addition of a single qubit to a QPU, the information the system contains doubles. Our 56-qubit System Model H2, for example, can hold quantum states that require 128*(2^56) bits worth of information to describe (with double-precision numbers) on a classical supercomputer, which is more information than the biggest supercomputer in the world can hold in memory.
The joint team made significant progress in approaching the Lattice Gauge Theory corresponding to Quantum Electrodynamics, the theory of light and matter. For the first time, they were able study the full wavefunction of a two-dimensional confining system with gauge fields and dynamical matter fields on a quantum processor. They were also able to visualize the confining string and the string-breaking phenomenon at the level of the wavefunction, across a range of interaction strengths.
The team approached the problem starting with the definition of the Hamiltonian using the InQuanto software package, and utilized the reusable protocols of InQuanto to compute both projective measurements and expectation values. InQuanto allowed the easy integration of measurement reduction techniques and scalable error mitigation techniques. Moreover, the emulator and hardware experiments were orchestrated by the Nexus online platform.
In one section of the study, a circuit with 24 qubits and more than 250 two-qubit gates was reduced to a smaller width of 15 qubits thanks our unique qubit re-use and mid-circuit measurement automatic compilation implemented in TKET.
This work paves the way towards using quantum computers to study lattice gauge theories in higher dimensions, with the goal of one day simulating the full three-dimensional Quantum Chromodynamics theory underlying the nuclear sector of the Standard Model of particle physics. Being able to simulate full 3D quantum chromodynamics will undoubtedly unlock many of Nature’s mysteries, from the Big Bang to the interior of neutron stars, and is likely to lead to applications we haven’t yet dreamed of.