Quantum remote control utilizing multiple degrees of freedom

Satish Kumar, Anirban Pathak

Quantum remote control, also known as quantum remote implementation of an operator (QRIO), enables the remote manipulation of an arbitrary quantum state by implementing a desired quantum operation at a distant location. Significant progress has recently been made in developing QRIO protocols and their variants. Most existing schemes employ hyperentangled states where entanglement is shared across multiple degrees of freedom (DOFs). However, these protocols typically exploit only one degree of freedom at a time. In this work, we propose a QRIO protocol that simultaneously utilizes the polarization and spatial DOFs of a two-qubit hyperentangled state to remotely implement an arbitrary hybrid operator on an unknown single-photon two-qubit hyperstate. The shared hyperentangled resource is realized using the polarization and spatial modes of photons, while the protocol is constructed using linear optical elements and cross-Kerr nonlinear interactions to facilitate effective photon-photon coupling. Furthermore, the effects of measurement errors arising from finite coherent state distinguishability and coherent state dissipation are analyzed and the corresponding success probability of the protocol is evaluated. The results demonstrate that an appropriate choice of the cross-Kerr phase shift and coherent state amplitude significantly enhances the protocol performance, making the proposed scheme a promising candidate for hybrid quantum communication and distributed quantum information processing.

Nguyen Ba An, Bich Thi Cao

Abstract Distributed quantum computation is a good solution for salable quantum computation within a quantum network each node of which just contains reasonably a few number of qubits. Controlled implementation of operators on states of a remote node is thus necessary. In this paper we propose protocols for three kinds of tasks of controlled implementation of operators on remote photon states via one hyperentangled Greenberger–Horne–Zeilinger state assisted with cross-Kerr nonlinearities: one with general operators and photon states in spatial degree of freedom (DOF), another one also with general operators but the photon state being in polarization DOF and the third one with a limited subset of operators acting on photon state in both spatial and polarization degrees of freedom. All the protocols are deterministic and performed in two steps under quantum control in each step.

Yuting Chen, Tzonelih Hwang

Peng Jia-yin

Cao Thi Bich, Nguyen Ba An

In this paper, we propose a new, to the best of our knowledge, protocol that enables two distant parties to prepare a photon hyperstate for each other encoded at the same time in both polarization and spatial-mode degrees of freedom. The bidirectional remote hyperstate preparation is demanded so that it is remotely controllable by a common supervisor. Such a task appears possible using a shared quantum channel made of five photons entangled simultaneously in the two corresponding degrees of freedom, the so-called hyperentanglement. We first design a near-deterministic scheme to produce a relevant five-photon hyperentanagled state to be served as the working nonlocal channel and then present our protocol for controlled bidirectional remote hyperstate preparation, which always is successful.