Quantum fluid reveals hidden states that can be switched with a magnetic field
Bose-Einstein condensates (BECs) are often described as a "fifth state of matter": a quantum state in which many particles lose their individual identities and behave as one collective object.
Bose-Einstein condensates (BECs) are often described as a "fifth state of matter": a quantum state in which many particles lose their individual identities and behave as one collective object.
The short version
- For more than 60 years, researchers have sought to create such condensates from excitons—electron-hole pairs—as a solid-state route to macroscopic quantum coherence, which is useful for quantum technologies.
- This has been difficult to realize in controllable semiconductor devices because optically generated excitons have very short lifetimes of around a billionth of a second, and BECs are normally attained with ultracold gases in a vacuum.
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What happened
The findings, published in Nature , reveal not only that the excitons form a BEC but also that the condensate has an internal structure that can be switched by a magnetic field. "While previous studies have shown that electrons and holes can bind into excitons, there wasn't an easy way to determine whether those excitons formed a condensate, nor could they ascertain what kind of internal quantum order that condensate has.
Why it matters
Our work provides a way to access that hidden structure directly," said principal investigator Feng Wang.
Summary by Nerd News Network. Read the full article at Phys.org via the links above and below.