Skip to main content

Entanglement revealed at the boiling point of interacting electrons

Entanglement revealed at the boiling point of interacting electrons

  • Date11 Feb 2019
  • Author Giovanni Sordi
  • Reading time 1min

Theoretical physicists uncover the role of the entanglement at a metal-insulator transition in correlated quantum matter.

2019 02 11 : CMT publication

The common experience of boiling water shows that dramatic changes in organisation of matter occur at phase transitions. At the quantum level, phase transitions also involve radical changes in quantum correlations and in the way constituents of matter are entangled.

In an article published today in Physical Review Letters, a team of theoretical physicists at Royal Holloway, at University of Sherbrooke in Canada, and at Brookhaven National Laboratory in the US have revealed the role of these quantum correlations at a fascinating phase transition.

The research was led by Giovanni Sordi, lecturer at Royal Holloway, and Professor André-Marie Tremblay at the University of Sherbrooke. The team worked with a mathematical model where the correlations between electrons turn a metal, where the electrons are free to move, into an insulator where the electrons refuse to move. This metal to insulator transition, known as Mott transition after the Nobel laureate Sir Nevill Mott, is a phenomenon central to quantum materials such as high-temperature superconductors.

Similarly to the familiar liquid-gas transition, this metal-insulator transition has two main features: it is abrupt and ends in a “boiling point” which evolves into a smooth change as the temperature rises. The central finding of the team’s work is that all these features are strongly imprinted on key measures of quantum correlations. Royal Holloway Master’s student Caitlin Walsh, the first author of the article, said: “This enables us to unlock the elusive role of the entanglement at this metal-insulator transition.”

The results of this theory are testable: the research provides experimenters using atoms at ultracold temperatures with a theoretical framework for existing results, and clear predictions of what signatures to look for in order to detect these distinctive patterns of quantum correlations. These results also raise surprising implications for other abrupt phase transitions ending in a “boiling point” in different quantum systems, such as those found in solids and quark matter.

Team members consist of Caitlin Walsh and Dr Giovanni Sordi at Royal Holloway, Dr Patrick Sémon at BNL, and professors David Poulin and André-Marie Tremblay at University of Sherbrooke. The research is published today in Physical Review Letters at this link. It is accompanied by an expanded article in Physical Review B at this link by the same authors.

Explore Royal Holloway

Get help paying for your studies at Royal Holloway through a range of scholarships and bursaries.

There are lots of exciting ways to get involved at Royal Holloway. Discover new interests and enjoy existing ones

Heading to university is exciting. Finding the right place to live will get you off to a good start

Whether you need support with your health or practical advice on budgeting or finding part-time work, we can help

Discover more about our 21 departments and schools

Find out why Royal Holloway is in the top 25% of UK universities for research rated ‘world-leading’ or ‘internationally excellent’

Royal Holloway is a research intensive university and our academics collaborate across disciplines to achieve excellence.

Discover world-class research at Royal Holloway

Discover more about who we are today, and our vision for the future

Royal Holloway began as two pioneering colleges for the education of women in the 19th century, and their spirit lives on today

We’ve played a role in thousands of careers, some of them particularly remarkable

Find about our decision-making processes and the people who lead and manage Royal Holloway today