Influence of Quantum Information Technology on International Security

Humanity is currently undergoing the fourth industrial revolution,characterized by advancements in artificial intelligence,clean energy,quantum information technology,virtual reality,and biotechnology.This technological revolution is poised to have a profound impact on the world.Quantum information technology encompasses both quantum computing and the transmission of quantum information.This article aims to integrate quantum information technology with international security concerns,exploring its implications for international security and envisioning its groundbreaking significance.

Experimental quantum state compression from two identical qubits to a qutrit

In the realm of modern information technology,data compression technology occupies a pivotal position.With advancements in quantum information technology,the need to compress large-scale qubits ensembles has become urgent,aiming to reduce the demand on quantum storage resources.However,existing quantum state compression schemes generally face a limitation:the particles before and after compression must reside in the same dimensional space.In specific scenarios,compressing qubits into particles of higher dimensions not only enhances the efficiency of quantum state compression but also further reduces the usage of quantum storage resources.Here we experimentally demonstrated a quantum state compression between particles of different dimensions,successfully compressing two qubits into a single qutrit.The average fidelity of the resulting qutrit with the ideal quantum state is 0.8835.Our study may have potential applications in future quantum information,such as increasing quantum communication bandwidth and reducing storage resource consumption in quantum computing.

Experimental demonstration of deterministic quantum search algorithms on a programmable silicon photonic chip

The Grover quantum search algorithm is a landmark quantum computing application, which has a speed advantage over classical algorithms for searching an unsorted database. For an√ unsorted database of N items, the classical algorithm needs to search O(N) times, while the Grover algorithm only needs O(√N) times. However, except for the special case of N = 4, the traditional Grover algorithm always has some probability of failure. To solve this problem, several schemes for deterministically performing quantum search have been proposed, but they all impose additional requirements on the query Oracle and cannot be implemented in many practical scenarios. Recently, Roy et al. [Phys. Rev. Res. 4, L022013(2022)] proposed a new deterministic quantum search scheme with no additional requirements on the query Oracle, which has the potential to perfectly replace the traditional Grover algorithm. In this study, we experimentally implement on a programmable silicon quantum photonic chip four deterministic quantum search algorithms, including the Roy algorithm, all of which obtained an average search success rate of over0.93, exceeding the theoretical maximum of 0.9074 that the traditional Grover algorithm can achieve. Our results demonstrate the feasibility and superiority of the deterministic quantum search algorithms and are expected to facilitate the wider application of these algorithms in future quantum information processing.

Optical studies of semiconductor perovskite nanocrystals for classical optoelectronic applications and quantum information technologies: a review

Semiconductor perovskite films are now being widely investigated as light harvesters in solar cells with ever-increasing power conversion efficiencies,which have motivated the fabrication of other optoelectronic devices,such as light-emitting diodes,lasers,and photodetectors.Their superior material and optical properties are shared by the counterpart colloidal nanocrystals(NCs),with the additional advantage of quantum confinement that can yield size-dependent optical emission ranging from the near-UV to near-infrared wavelengths.So far,intensive research efforts have been devoted to the optical characterization of perovskite NC ensembles,revealing not only fundamental exciton relaxation and recombination dynamics but also lowthreshold amplified spontaneous emission and novel superfluorescence effects.Meanwhile,the application of single-particle spectroscopy techniques to perovskite NCs has helped to resolve a variety of optical properties for which there are few equivalents in traditional colloidal NCs,mainly including nonblinking photoluminescence,suppressed spectral diffusion,stable exciton fine structures,and coherent singlephoton emission.While the main purpose of ensemble optical studies is to guide the smooth development of perovskite NCs in classical optoelectronic applications,the rich observations from single-particle optical studies mark the emergence of a potential platform that can be exploited for quantum information technologies.