arXiv subjects

Si-Qi Du

Publications and source records attributed to Si-Qi Du.

3 recordsLinked to original sources

arXiv2026

Entanglement concentration of high-dimensional unknown partially entangled state

High-dimensional quantum systems offer a number of advantages in larger information capacity, stronger noise resiliency, higher improved efficiency and accuracy over the qubit systems. In quantum communication the maximally entangled states will inevitably become mixed states or less-entangled pure states by the channel noise during the practical transmission or storage. We propose a universal scheme to concentrate nonlocal high-dimensional generalized Bell states with unknown parameters. After the cross-Kerr nonlinearities, $X$-quadrature homodyne measurements, and single-partite projection measurements are performed only at Bob's site, a two-qutrit maximally entangled Bell state can be distilled, while previous entanglement concentration protocols (ECPs) mostly focused on two-level qubit systems. The concentrated partially entangled qubit states, reserved as the by-product are the fascinating resources for some quantum information processing tasks. Moreover, single-qutrit projection measurement, the key ingredient for our ECP with unknown parameters, are completed by using linear optical elements. Additionally, linear optical high-dimensional ECP with known parameters are also designed.

quant-ph↗

arXiv2026

Remote state preparation of single-partite high-dimensional states in complex Hilbert spaces

High-dimensional quantum systems offer a new playground for quantum information applications due to their remarkable advantages such as higher capacity and noise resistance. We propose potentially practical schemes for remotely preparing four- and eight-level equatorial states in complex Hilbert spaces exactly by identifying a set of orthogonal measurement bases. In these minimal-resource-consuming schemes, both pre-shared maximally and non-maximally entangled states are taken into account. The three-, five-, six-, and seven-level equatorial states in complex Hilbert spaces can also be obtained by adjusting the parameters of the desired states. The evaluations indicate that our high-dimensional RSP schemes might be possible with current technology. The collection operations, necessary for our high-dimensional RSP schemes via partially entangled channels, can be avoided by encoding the computational basis in the spatial modes of single-photon systems.

quant-ph↗

arXiv2025

Bidirectional controlled quantum state preparation in high-dimensional quantum system

High-dimensional quantum system exhibits unique advantages over the qubit system in some quantum information processing tasks. We present a program for implementing deterministic bidirectional controlled remote quantum state preparation (BCRSP) in arbitrary $N$-dimensional (quNit) system. By introducing two generalized Greenberger-Horne-Zeilinger (GHZ) states as quantum channels, two communication parties can simultaneously prepare a single-particle high-dimensional state at each other's site under the control of Charlie. Compared with the previous counterparts, the significant advantage of our scheme is that the high-dimensional CNOT operations are not required. Moreover, the performance our scheme are evaluated. The evaluation of the performance shows that if the quNit is encoded in the spatial mode of single photons, our scheme can be accomplished solely using only linear optical elements.

quant-ph↗