Thursday, 02 December 2021
New research using a highly controllable quantum processor has provided new insights into ‘exotic’ states of matter that could lead to new ways to improve quantum computers.
Scientists from the University of Nottingham and Technical University of Munich (TUM) collaborated with the Google Quantum AI team and used a highly controllable quantum processor to simulate the ground state of a so-called toric code Hamiltonian – an archetypical model system in modern condensed matter physics, which was originally proposed in the context of quantum error correction.
While the number of qubits and the stability of quantum states are still limiting actual quantum computing devices, there are questions where these processors are already able to leverage their enormous computing power. This new research published today in Science helps to understand this.
What would it be like if we lived in a flat two-dimensional world? Physicists predict that quantum mechanics is even stranger in that case and results in exotic particles — so-called “anyons”— that cannot exist in the three-dimensional world we live in. This unfamiliar world is not just a curiosity but may be key to unlocking quantum materials and technologies of the future. The research team used a highly controllable quantum processor to simulate these states of quantum matter.
Emergent quantum particles in two dimensional systems
All particles in our universe come in two flavors, bosons or fermions. In the three-dimensional world we live in, this observation stands firm. However, it was theoretically predicted almost 50 years ago that other types of particles, dubbed anyons, could exist when matter is confined to two dimensions.
Twisting pairs of these anyons by moving them around one another unveils their exotic properties—physicists call it braiding statistics
While these anyons do not appear as elementary particles in our universe, it turns out that anyonic particles can emerge as collective excitations in so-called topological phases of matter, for which the Nobel prize was awarded in 2016.
A simple picture for these collective excitations is "the wave" in a stadium crowd--it has a well-defined position, but it cannot exist without the thousands of people that make up the crowd. However, realizing and simulating such topologically ordered states experimentally has proven to be extremely challenging.
Quantum processors as a platform for controlled quantum simulations
In landmark experiments, the researchers programmed Google’s quantum processor to simulate these two-dimensional states of quantum matter. “Google’s quantum processor named ‘Sycamore’ can be precisely controlled and is a well-isolated quantum system, which are key requirements for performing quantum computations,” says Kevin Satzinger, a scientist from the Google team.
The researchers came up with a quantum algorithm to realize a state with topological order, which was confirmed by simulating the creation of anyon excitations and twisting them around one another. Fingerprints from long-range quantum entanglement could be confirmed in their study. As a possible application, such topologically ordered states can be used to improve quantum computers by realizing new ways of error correction. First steps toward this goal have already been achieved in their work.
“Near term quantum processors represent an ideal platform to explore the physics of exotic quantum phases matter,” says Prof. Frank Pollmann from TUM. In the near future, quantum processors promise to solve problems that are beyond the reach of current classical supercomputers. In particular, they offer new opportunities to unlock the mysteries of novel quantum materials.
More information is available from Dr Adam Smith on firstname.lastname@example.org
Our academics can now be interviewed for broadcast via our Media Hub, which offers a Quicklink fixed camera and ISDN line facilities at Jubilee campus. For further information please contact a member of the Press Office on +44 (0)115 951 5798, email
For up to the minute media alerts,
follow us on Twitter
Notes to editors:
The University of Nottingham is a research-intensive university with a proud heritage. Studying at the University of Nottingham is a life-changing experience and we pride ourselves on unlocking the potential of our students. We have a pioneering spirit, expressed in the vision of our founder Sir Jesse Boot, which has seen us lead the way in establishing campuses in China and Malaysia - part of a globally connected network of education, research and industrial engagement. Ranked 103rd out of more than 1,000 institutions globally and 18th in the UK by the QS World University Rankings 2022, the University’s state-of-the-art facilities and inclusive and
disability sport provision is reflected in its crowning as The Times and Sunday Times Good University Guide 2021 Sports University of the Year. We are ranked eighth for research power in the UK according to
REF 2014. We have
six beacons of research excellence helping to transform lives and change the world; we are also a major employer and industry partner - locally and globally. Alongside Nottingham Trent University, we lead the Universities for Nottingham initiative, a pioneering collaboration which brings together the combined strength and civic missions of Nottingham’s two world-class universities and is working with local communities and partners to aid recovery and renewal following the COVID-19 pandemic.