Novel thermal phases of topological quantum matter in the lab

April 18, 2018, Universidad Complutense de Madrid
Quantum circuit implemented on the IBM Quantum Experience platform in order to measure the topological Uhlmann phase. Credit: Oscar Oviyuela et al.

For the first time, a group of researchers from Universidad Complutense de Madrid, IBM, ETH Zurich, MIT and Harvard University have observed topological phases of matter of quantum states under the action of temperature or certain types of experimental imperfections. The experiment was conducted using quantum simulator at IBM.

Quantum simulators were first conjectured by the Nobel Prize laureate Richard Feynman in 1982. Ordinary classical computers are inefficient at simulating systems of interacting quantum particles These new simulators are genuinely quantum and can be controlled very precisely. They replicate other quantum systems that are harder to manipulate and whose physical properties remain very much unknown.

In an article published in the journal Quantum Information, the researchers describe using a with superconducting qubits at IBM to replicate materials known as topological insulators at finite temperature, and measure for the first time their topological quantum phases.

Topological phases of matter represent a very exciting and active field of research that is revolutionising the understanding of nature and material science. The study of these novel phases of matter has given rise to new materials such as , which behave as regular insulators in the bulk and as metals at the boundaries. These boundary electronic currents have polarised spin.

Since the discovery of , researchers have looked for innovative ways to maintain their properties at finite temperature. Previous theoretical works of the researchers at Universidad Complutense proposed a new topologial quantum phase, the Uhmann phase, to characterise these phases of matter in thermal systems. The Uhlmann phase allows researchers to generalise the of matter to systems with temperature.

The results represent the first measurement of topological quantum phases with temperature, and advance the synthesis and control of topological matter using quantum technologies. Among other applications, topological quantum matter could be used as hardware for future computers due to its intrinsic robustness against errors. The experimental results presented in this work show how these can also be robust against temperature effects.

Explore further: Physicists quantum simulate topological materials with ultracold atoms

More information: O. Viyuela et al, Observation of topological Uhlmann phases with superconducting qubits, npj Quantum Information (2018). DOI: 10.1038/s41534-017-0056-9

Related Stories

Key component to scale up quantum computing

November 28, 2017

A team at the University of Sydney and Microsoft, in collaboration with Stanford University in the US, has miniaturised a component that is essential for the scale-up of quantum computing. The work constitutes the first practical ...

Recommended for you

Taking a close look at bacteria

October 23, 2018

Yong Wang, assistant professor of physics, and graduate student Asmaa Sadoon have been studying how molecules travel through bacterial cytoplasm in order to understand more about how these tiny organisms function. Using new ...

Researchers validate 80-year-old ferroelectric theory

October 23, 2018

Researchers have successfully demonstrated that hypothetical particles that were proposed by Franz Preisach in 1935 actually exist. In an article published in Nature Communications, scientists from the universities in Linköping ...

Understanding the building blocks for an electronic brain

October 22, 2018

Computer bits are binary, with a value of zero or one. By contrast, neurons in the brain can have many internal states, depending on the input that they receive. This allows the brain to process information in a more energy-efficient ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.