We propose a fast, robust, and long-distance quantum state transfer (QST) protocol via a splicing Su-Schrieffer-Heeger (SSH) chain, where the interchain couplings vary with the change in the phase parameter and the single or splicing SSH chain can be designed by adjusting it. It is found that the existence of a zero-energy interface state (IFS) not only can improve the speed of QST but also can realize long-distance QST. Furthermore, we give the phase diagram in the parameter space of the transfer time $T$ and the system's size $N$ , where the different regions that can successfully implement QST via a single- or splicing-SSH-chain protocol are given. Therefore, we can choose the optimal QST protocol by adjusting only the phase parameter for different transfer times and system sizes. By numerically investigating the resilience of each protocol to static disorder, we reveal that the splicing-SSH-chain protocol is quite robust to both diagonal and off-diagonal disorders and clearly outperforms the single-SSH-chain protocol. By considering the environmental influence, rendering the Hamiltonian non-Hermitian by allowing energy to radiate away, our work shows that the QST protocol assisted by zero-energy IFS is more robust than previously expected and also outperforms the single-SSH-chain protocol.We propose a fast, robust, and long-distance quantum state transfer (QST) protocol via a splicing Su-Schrieffer-Heeger (SSH) chain, where the interchain couplings vary with the change in the phase parameter and the single or splicing SSH chain can be designed by adjusting it. It is found that the existence of a zero-energy interface state (IFS) not only can improve the speed of QST but also can realize long-distance QST. Furthermore, we give the phase diagram in the parameter space of the transfer time $T$ and the system's size $N$, where the different regions that can successfully implement QST via a single- or splicing-SSH-chain protocol are given. Therefore, we can choose the optimal QST protocol by adjusting only the phase parameter for different transfer times and system sizes. By numerically investigating the resilience of each protocol to static disorder, we reveal that the splicing-SSH-chain protocol is quite robust to both diagonal and off-diagonal disorders and clearly outperforms the single-SSH-chain protocol. By considering the environmental influence, rendering the Hamiltonian non-Hermitian by allowing energy to radiate away, our work shows that the QST protocol assisted by zero-energy IFS is more robust than previously expected and also outperforms the single-SSH-chain protocol.

Physical Review AAug 19, 202222 citations

Quantum State Transfer in One-dimensional Spin Chains with a Moving Potential

Zhang Yong-mei

Inspired by the phenomenon that disorder can restrain quantum state transfer in spin chain,we verify the assumption that quantum state can penetrate potential barrier of a certain magnetic density with low probability.Finite square potential well,cosine potential well and parabolic potential well are discussed.Quantum state is restrained at the bottom of the moving potential well.Regarding the spin chain as a damping channel,relations between damping coefficient γ and the strength of magnetic field are studied.Low damping coefficient is obtained under a certain magnetic density.Quantum state is able to transfer a long distance with high fidelity.This scheme is robust in the presence of disorder.Inspired by the phenomenon that disorder can restrain quantum state transfer in spin chain,we verify the assumption that quantum state can penetrate potential barrier of a certain magnetic density with low probability.Finite square potential well,cosine potential well and parabolic potential well are discussed.Quantum state is restrained at the bottom of the moving potential well.Regarding the spin chain as a damping channel,relations between damping coefficient γ and the strength of magnetic field are studied.Low damping coefficient is obtained under a certain magnetic density.Quantum state is able to transfer a long distance with high fidelity.This scheme is robust in the presence of disorder.

Acta Sinica Quantum OpticaJan 1, 20110 citations

Memory-assisted advantage for state transfer in disordered quantum many-body scar system

Paranjoy Chaki, Ujjwal Sen

We analyze how memory in disorder facilitates quantum communication in many-body scar systems. We consider three distinct types of disorder, viz., memoryful, and memoryless uniform and Gaussian, and compare their respective performances in facilitating quantum state transfer. Using the maximum transfer fidelity and fidelity area as figures of merit, we find that memoryful disorder yields a better performance than the memoryless disordered channels. Furthermore, the maximum transfer fidelity exhibits an initial parabolic decay with disorder strength, followed by a linear decrease, for all the disorder models considered. We introduce a degree of scarness, and show that it is higher for memoryful disorder in comparison to memoryless disorders, implying a role of scarness in the quantum state transfer protocol. We further perform a scaling analysis, revealing that memory effect in disorder is not only beneficial for short-distance but also long-distance quantum state transfer. Finally, we show that the state yielding the maximum transfer fidelity has larger inverse participation ratio for memoryful disorder in comparison to the other two disorders, highlighting the role of nonergodicity in enhancing state transfer.We analyze how memory in disorder facilitates quantum communication in many-body scar systems. We consider three distinct types of disorder, viz., memoryful, and memoryless uniform and Gaussian, and compare their respective performances in facilitating quantum state transfer. Using the maximum transfer fidelity and fidelity area as figures of merit, we find that memoryful disorder yields a better performance than the memoryless disordered channels. Furthermore, the maximum transfer fidelity exhibits an initial parabolic decay with disorder strength, followed by a linear decrease, for all the disorder models considered. We introduce a degree of scarness, and show that it is higher for memoryful disorder in comparison to memoryless disorders, implying a role of scarness in the quantum state transfer protocol. We further perform a scaling analysis, revealing that memory effect in disorder is not only beneficial for short-distance but also long-distance quantum state transfer. Finally, we show that the state yielding the maximum transfer fidelity has larger inverse participation ratio for memoryful disorder in comparison to the other two disorders, highlighting the role of nonergodicity in enhancing state transfer.

quant-pharXiv:2606.18720Jun 18, 20260 citations

Robust Quantum State Transfer in Random Unpolarized Spin Chains

Norman Y. Yao, Liang Jiang, Alexey Vyacheslavovich Gorshkov +4 more

We propose and analyze a new approach for quantum state transfer between remote spin qubits. Specifically, we demonstrate that coherent quantum coupling between remote qubits can be achieved via certain classes of random, unpolarized (infinite temperature) spin chains. Our method is robust to coupling-strength disorder and does not require manipulation or control over individual spins. In principle, it can be used to attain perfect state transfer over an arbitrarily long range via purely Hamiltonian evolution and may be particularly applicable in a solid-state quantum information processor. As an example, we demonstrate that it can be used to attain strong coherent coupling between nitrogen-vacancy centers separated by micrometer distances at room temperature. Realistic imperfections and decoherence effects are analyzed.We propose and analyze a new approach for quantum state transfer between remote spin qubits. Specifically, we demonstrate that coherent quantum coupling between remote qubits can be achieved via certain classes of random, unpolarized (infinite temperature) spin chains. Our method is robust to coupling-strength disorder and does not require manipulation or control over individual spins. In principle, it can be used to attain perfect state transfer over an arbitrarily long range via purely Hamiltonian evolution and may be particularly applicable in a solid-state quantum information processor. As an example, we demonstrate that it can be used to attain strong coherent coupling between nitrogen-vacancy centers separated by micrometer distances at room temperature. Realistic imperfections and decoherence effects are analyzed.

arXiv:1011.2762Physical Review LettersJan 27, 2011234 citations

T

and the system's size

N

, where the different regions that can successfully implement QST via a single- or splicing-SSH-chain protocol are given. Therefore, we can choose the optimal QST protocol by adjusting only the phase parameter for different transfer times and system sizes. By numerically investigating the resilience of each protocol to static disorder, we reveal that the splicing-SSH-chain protocol is quite robust to both diagonal and off-diagonal disorders and clearly outperforms the single-SSH-chain protocol. By considering the environmental influence, rendering the Hamiltonian non-Hermitian by allowing energy to radiate away, our work shows that the QST protocol assisted by zero-energy IFS is more robust than previously expected and also outperforms the single-SSH-chain protocol.