South China Normal Team Achieves Thouless Pumping Via Discrete Steps

Thouless pumping, a celebrated topological effect enabling quantized particle transport with potential applications in quantum technologies, has been investigated by South China Normal University. Standard adiabatic pumping theory dictates that the Hamiltonian must be varied continuously and slowly throughout the entire pumping process. The investigation shows that Thouless pumping can be realised using discrete sampling of the Hamiltonian, thus removing the traditional requirement for continuous and gradual control changes. Researchers specifically selected particular parameter points within the Hamiltonian to enable conventional continuous quantum adiabatic evolution. Quantized charge transfer via strategic discrete control of topological systems This removes constraints previously considered essential regarding the rate of change in controlling parameters and opens avenues for simplified experimental setups within quantum technologies. The researchers demonstrated that adiabatic evolution, important for Thouless pumping, can be realised through strategically selected parameter points rather than smooth transitions, fulfilling established criteria for quantum adiabaticity. Simulations revealed y(T)/d, representing transported particles normalised by distance, approached one for both schemes when utilising an increasing number, P, of pulses. Calculations showed similar performance was achieved despite using discrete parameter alterations compared to standard continuous modulation techniques. Further analysis introduced artificial errors into the system by varying the Hamiltonian; this technique maintained near-quantized performance more effectively as pulse numbers increased and total evolution time lengthened. These results confirm an adiabatic process but do not yet address scalability beyond relatively small systems or challenges in maintaining coherence over extended timescales needed for practical quantum devices. Hamiltonian dynamics enabling adiabatic Thouless pumping realisation Applying the Hamiltonian at these selected points induces a geodesic evolution for the pseudospin with a given quasimomentum, realising an adiabatic evolution for Thouless pumping according to a necessary and sufficient condition for quantum adiabatic evolution. Originally introduced by Thouless, this phenomenon demonstrates that adiabatically cycling modulation of a one-dimensional periodic potential can yield quantized particle transport per cycle; it has been widely studied as a fundamental effect in condensed matter and atomic physics. Characterised by its Chern number, Thouless pumping serves as a dynamical analogue of the integer quantum Hall effect, rendering resulting particle transport intrinsically durable against weak disorder and interactions. Experimental demonstrations have occurred across various platforms including ultracold atom and photonic systems over the past decade. The conventional approach involves changing the Hamiltonian continuously and slowly according to established conditions for quantum adiabatic processes. This slow continuous change imposes challenges for experimentally implementing Thouless pumping due to long evolution times. A recent study proposed shortcuts to adiabaticity (STA) to accelerate this process; however, it relies on highly intricate auxiliary control fields making implementation difficult. Traditional conditions can be problematic because they require precise parameter control. Piecewise-constant Hamiltonians are possible for suppressing non-adiabatic transitions as indicated by a necessary and sufficient condition. Experimental verification suggests that fast averaging via dynamic phase factors is the key mechanism rather than slow variation. Remarkably, this enables breaking the quantum adiabatic speed limit by jumping along a geodesic path. Accelerated schemes have been developed for qubits, three-level systems, multisqueezed states, and more general multi-level quantum systems based on this new condition. Until now its application in condensed matter physics remained unexplored despite theoretical applications to these simple systems; conventional control was modified into a fundamentally new form based on established criteria for quantum adiabatic evolution. Specifically, applying it only at discrete parameter points within the space used for Thouless pumping is possible instead of continuous Hamiltonian changes required under traditional conditions. This allows suppression of nonadiabatic transitions while simplifying experimental complexity because fewer control parameters are needed to be compared with standard methods. Unlike STA techniques requiring complex auxiliary fields, this method is inherently adiabatic providing a route to manipulate complex quantum systems without sophisticated controls. This paper is organised as follows: Section II develops Thouless pumping using discrete jumping of the adiabatic Hamiltonian; Section III presents numerical studies in momentum and position spaces; conclusions appear in Section IV. Throughout this work units are adopted in which ħ= 1. A different function will be used for φ(t) by our jumping approach later on. Here J represents average hopping strength while δ0 and ∆0 are modulation amplitudes of hopping and on-site energy respectively. Thouless pumping represents a topological effect enabling quantized particle transport and offering potential applications in quantum technologies. However, it can be realised using discrete sampling of the Hamiltonian which removes this requirement for gradual change. Specific parameter points are selected to allow conventional adiabatic evolution inducing geodesic movement of pseudospin alongside given quasimomentum; this achieves an adiabatic evolution consistent with conditions required for quantum adiabaticity. Thouless pumping represents a topological effect enabling quantized particle transport with potential applications in quantum technologies. Conventional adiabatic theory requires continuous and slow variation of the Hamiltonian during this process. Selected points within the Hamiltonian’s parameters induce conventional quantum adiabatic evolution then applied, resulting in geodesic pseudospin evolution with given quasimomentum. This ensures an adiabatic evolution according to a necessary and sufficient condition for quantum adiabaticity. Removing the requirement for traversing all space offers deeper insight while reducing experimental complexity where realisation is continuously inaccessible or problematic due to hardware limitations. Instead of varying continuously over its range, sample φ = φ1, φ2,. In following sections we determine a value for tp during pumping. Researchers demonstrated Thouless pumping using discrete sampling of the Hamiltonian, rather than requiring continuous changes to its parameters. This means quantized particle transport can be achieved without needing precise and slow control over the system throughout the process. Authors suggest this approach offers insight into the phenomenon while potentially simplifying experimental realisation where continuous variation is difficult or impossible. 👉 More information🗞 Thouless pumping via discrete jumping of the adiabatic Hamiltonian✍️ Lang Yu, Yihan Wu and Zhen-Yu Wang🧠 ArXiv: https://arxiv.org/abs/2609.17116 More like thisPhysicsAumann’s theorem gets a quantum boost for all generalized probability theoriesPhysicsLHCb detector boosts precision of muon asymmetry measurementQuantum Research NewsStanford captures a quantum jump in sound for the first timePhysicsCERN brought physicists and artists together to explore quantum theoryStay currentSee today’s quantum computing news on Quantum Zeitgeist for the latest breakthroughs in qubits, hardware, algorithms, and industry deals. Tags: