Non-Abelian anyons: anything but easy - Physics World

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Your Physics World account is separate to any IOP accounts you may have.Note: The verification e-mail to complete your account registration should arrive immediately. However, in some cases it takes longer. Don't forget to check your spam folder.If you haven't received the e-mail in 24 hours, please contact customerservices@ioppublishing.org.Please enter the e-mail address you used to register to reset your passwordNote: The verification e-mail to change your password should arrive immediately. However, in some cases it takes longer. Don't forget to check your spam folder.If you haven't received the e-mail in 24 hours, please contact customerservices@ioppublishing.orgThank you for registering with Physics World If you'd like to change your details at any time, please visit My accountA team of researchers from the USA have observed spontaneously broken rotational symmetry in fractional quantum Hall statesTopological quantum computing is a proposed approach to building quantum computers that aims to solve one of the biggest challenges in quantum technology: error correction.In conventional quantum systems, qubits are extremely sensitive to their environment and even tiny disturbances can cause errors. Topological quantum computing addresses this by encoding information in the global properties of a system: the topology of certain quantum states.These systems rely on the use of non-Abelian anyons, exotic quasiparticles that can exist in two-dimensional materials under special conditions.The main challenge faced by this approach to quantum computing is the creation and control of these quasiparticles.One possible source of non-Abelian anyons is the fractional quantum Hall state (FQH): an exotic state of matter which can exist at very low temperatures and high magnetic fields.These states come in two forms: even-denominator and odd-denominator. Here, we’re interested in the even-denominator states – the more interesting but less well understood of the two.In this latest work, researchers have observed this exotic state in gallium arsenide (GaAs) two-dimensional hole systems.Typically, FQH states are isotropic, showing no preferred direction. Here, however, the team found states that are strongly anisotropic, suggesting that the system spontaneously breaks rotational symmetry.This means that it forms a nematic phase – similar to liquid crystals – where molecules align along a direction without forming a rigid structure.This spontaneous symmetry breaking adds complexity to the state and can influence how quasiparticles behave, interact, and move.The observation of the existence of spontaneous nematicity in an even-denominator fractional quantum Hall state is the first of its kind.Although there are many questions left to be answered, the properties of this system could be hugely important for topological quantum computers as well as other novel quantum technologies.Even-denominator fractional quantum Hall states with spontaneously broken rotational symmetry – IOPscienceC. Wang et al 2025 Rep. Prog. Phys. 88 100501 The Progress In series is an evolving network of journals that curate, enhance, and amplify essential research, aiming to unite multidisciplinary global research communities. The journals share a joint mission to publish ground-breaking new research and authoritative invited reviews of the highest quality and significance.