Quantum transport efficiency is influenced by mechanisms beyond coherence, including correlated disorder, which can balance localization and mobility to produce anomalous phenomena such as quantum rogue waves. Motivated by recent findings, we investigate the impact of correlated on-site energies in a linear quantum chain modeling a biological ion channel. The system is described by a tight-binding Hamiltonian with Lindblad operators representing source and drain. The average traversal time across the channel increases logarithmically with the correlation parameter, mirroring the growth of rogue-wave probability and indicating the emergence of temporary trapped states that slow transport. These results demonstrate that correlated disorder significantly influences ion transport even in small disordered systems.
Quantum transport efficiency is influenced by mechanisms beyond coherence, including correlated disorder, which can balance localization and mobility to produce anomalous phenomena such as quantum rogue waves. Motivated by recent findings, we investigate the impact of correlated on-site energies in a linear quantum chain modeling a biological ion channel. The system is described by a tight-binding Hamiltonian with Lindblad operators representing source and drain. The average traversal time across the channel increases logarithmically with the correlation parameter, mirroring the growth of rogue-wave probability and indicating the emergence of temporary trapped states that slow transport. These results demonstrate that correlated disorder significantly influences ion transport even in small disordered systems.
A study published in Frontiers in Quantum Science and Technology elucidates that correlated disorder acts as a tunable quantum switch regulating the conduction and trapping of ions, by modeling biological ion channels as a linear quantum chain. As analyzed through a tight-binding Hamiltonian and Lindblad operators, the average traversal time of ions increases logarithmically according to the correlation parameter of the disorder, and it was confirmed that this mirrors the growth of quantum rogue wave probability. It mathematically proves that living organisms can precisely control the opening and closing of channels by adjusting microscopic disorder to quantum mechanically express transient trapped states inside the ion passageway. [Quantum Biology Society] Ion channels, which regulate the flow of ions across the cell membrane, serve as nanoscale gatekeepers essential for sustaining life. Until now, the opening and closing mechanism of ion channels has been explained by classical protein structural changes, but recently, the introduction of quantum mechanical transport models is opening a new perspective on observing life phenomena. The paper titled "Correlated disorder as a tunable switch between trapping and conduction in quantum ion channels," published in the international journal Frontiers in Quantum Science and Technology, mathematically proved the possibility that ion channels are sophisticated quantum switches utilizing quantum rogue waves (anomalous waves that become abnormally massive, amplifying like ocean waves). A joint research team including Iara Patrícia Da Silva Ramos, Rafael Gandolfi Lanzini, Leonardo Brunnet, and Sandra D. Prado from the Institute of Physics at the Federal University of Rio Grande do Sul in Brazil spearheaded this innovative study. ■ Quantum Chains and Rogue Waves in Ion Channels The research team modeled a biological ion channel (the selectivity filter of the KcsA potassium channel) as a one-dimensional linear quantum chain and precisely investigated the impact of correlated disorder—microscopic structural fluctuations within the protein—on the system through a tight-binding Hamiltonian and the Lindblad master equation. The analysis confirmed that as the balance between localization and mobility within the channel is regulated by disorder, anomalous wave phenomena such as quantum rogue waves, which coagulate abnormally massive energy, occur. ■ The Quantum Switch of Trapped States Controlled by Disorder According to the results of 10,000 independent ensemble simulations performed by the research team, the average traversal time of ions crossing the channel increased sharply in a logarithmic form in proportion to the correlation parameter (A) of the disorder. Surprisingly, this delay in traversal time perfectly matched the increased probability of quantum rogue waves occurring. This means that as the correlation of disorder becomes stronger, transient trapped states that delay the movement of particles are quantum mechanically expressed inside the ion channel. Ultimately, this suggests that living organisms possess highly evolved systems that actively adjust microscopic disorder within cells, precisely controlling them like a quantum switch alternating between conduction and trapping in ion passageways. https://www.frontiersin.org/journals/quantum-science-and-technology/articles/10.3389/frqst.2025.1725290/full
We investigate in detail the transference of quantum states in a disordered channel. We consider a one-dimensional tight-binding model consisting of a source S connected to a receiver R throughout a disordered channel. The disorder distribution contains a single tunable spatial correlation length. We demonstrate that the disorder correlation length plays a relevant role within the localization properties of the channel. The hopping parameter between the sites S and R and the channel are also adjustable parameters. We investigate the possibility of transference of quantum states along this quantum channel model and describe the optimal conditions for the occurrence of a high fidelity process.
The transport of excitations governs fundamental properties of matter. Particularly rich physics emerges in the interplay between disorder and environmental noise, even in small systems such as photosynthetic biomolecules. Counterintuitively, noise can enhance coherent quantum transport, which has been proposed as a mechanism behind the high transport efficiencies observed in photosynthetic complexes. This effect has been called ``environment-assisted quantum transport''. Here, we propose a quantum simulation of the excitation transport in an open quantum network, taking advantage of the high controllability of current trapped-ion experiments. Our scheme allows for the controlled study of various different aspects of the excitation transfer, ranging from the influence of static disorder and interaction range, over the effect of Markovian and non-Markovian dephasing, to the impact of a continuous insertion of excitations. Our paper discusses experimental error sources and realistic parameters, showing that it can be implemented in state-of-the-art ion-chain experiments.
discrimination rate between ions). It is made of four strands as the backbone, and each strand is composed of sequences of five amino acids connected by peptide units H-N-C=O in which the main molecules in the backbone that interact with ions in the filter are carbonyl (C=O) groups that mimic the transient interactions of ion with binding sites during ion conduction. It has been suggested that quantum coherence and possible emergence of resonances in the backbone carbonyl groups may play a role in mediating ion conduction and selectivity in the filter. Here, we investigate the influence of noise and disorder on the efficiency of excitation energy transfer (EET) in a linear harmonic chain of N = 5 sites with dipole-dipole couplings as a simple model for one P-loop strand of the selectivity filter backbone in biological ion channels. We include noise and disorder inherent in real biological systems by including spatial disorder in the chain, and random noise within a weak coupling quantum master equation approach. Our results show that disorder in the backbone considerably reduces EET, but the addition of noise helps to recover high EET for a wide range of system parameters. Our analysis may help for better understanding of the coordination of ions in the filter as well as the fast and efficient functioning of the selectivity filters in ion channels.
The way in which energy is transported through an interacting system governs fundamental properties in nature such as thermal and electric conductivity or phase changes. Remarkably, environmental noise can enhance the transport, an effect known as environment-assisted quantum transport (ENAQT). In this Letter, we study ENAQT in a network of coupled spins subject to engineered static disorder and temporally varying dephasing noise. The interacting spin network is realized in a chain of trapped atomic ions, and energy transport is represented by the transfer of electronic excitation between ions. With increasing noise strength, we observe a crossover from coherent dynamics and Anderson localization to ENAQT and finally a suppression of transport due to the quantum Zeno effect. We find that in the regime where ENAQT is most effective, the transport is mainly diffusive, displaying coherences only at very short times. Further, we show that dephasing characterized by non-Markovian noise can maintain coherences longer than white noise dephasing, with a strong influence of the spectral structure on the transport efficiency. Our approach represents a controlled and scalable way to investigate quantum transport in many-body networks under static disorder and dynamic noise.
Quantum transport in disordered systems poses intriguing fundamental questions about the interplay of disorder, interactions, and decoherence, with important implications for nanoscale energy transfer and quantum information transfer. Here, we investigate the emergence of multiple transport timescales in the dissipative dynamics of a spin impurity coupled to a small, spatially disordered network of spins. Using a two-dimensional tight-binding model with dipolar interactions and local dephasing, we demonstrate that geometric heterogeneity leads to hierarchical coupling strengths and pronounced separation of dynamical timescales. By analyzing different metrics for dynamics, we identify distinct relaxation timescales associated with cluster-level equilibration and global equilibration. A minimal three-site model reveals the physical origin of the longest timescale: strong internal hybridization generates an effective detuning that suppresses transfer to other weakly coupled sites, yielding a parametrically enhanced relaxation time in the weak-dephasing regime. We corroborate this picture with nonequilibrium steady-state transport calculations and simulations of disordered spin configurations, demonstrating orders-of-magnitude slowing of relaxation when hierarchical couplings are present. Our results highlight the central role of geometry and connectivity in spin networks and open quantum systems in general, and provide experimentally relevant predictions for relaxation times in small spin baths.