Chongfan Technology
News
16
2025
-
07
Quantum logic gates based on single-piece gradient metasurface
Author:
In today's rapidly developing quantum information technology, realizing efficient and highly integrated quantum logic gates is one of the key challenges in the field of integrated quantum optics. Recently, the research teams of Gu Ying and Gong Qihui from Peking University, in collaboration with Professor Li Guixin from Southern University of Science and Technology and Professor Ren Xifeng from University of Science and Technology of China, have made new progress in the integration of photonic quantum logic devices. The research team proposed a theoretical scheme for realizing a quantum controlled-phase gate based on a single-chip gradient metasurface, providing a new technological path for ultra-compact on-chip quantum information processing. The relevant results are published in Quantum CZ gates on a single gradient metasurface ”为题发表于 'Light: Science & Applications' Liu Qi, a doctoral student at Peking University, is the first author of the paper, and Professor Gu Ying from Peking University is the corresponding author.
Integrated photonic quantum computing and on-chip photonic quantum information processing are rapidly developing frontier fields, promising to revolutionize traditional computing and communication technologies. The realization of two-bit entangled quantum gates, such as the controlled-NOT (CNOT) and controlled-phase (CZ) gates, is fundamental to accomplishing general quantum information processing tasks. However, integrating quantum logic gates into scalable and efficient chip systems remains a significant challenge. Conventional quantum logic gate schemes typically rely on bulky optical beam splitters or waveguides, which have many limitations in terms of device size, scalability, and efficiency. Simultaneously, high-fidelity quantum logic gate operations are difficult to achieve due to manufacturing asymmetries, crosstalk, and unnecessary losses.
The rise of metasurface technology has provided new ideas for solving this problem. A metasurface is a novel planar optical platform that can precisely manipulate the phase, amplitude, and polarization of light at the subwavelength scale. In addition, the compact structure of the metasurface allows it to be compatible with existing chip manufacturing processes, making it possible to realize high-density integrated quantum photonic chips. These characteristics make metasurfaces exhibit enormous application potential in the field of quantum optics, especially in the preparation, manipulation, and measurement of quantum states. Although exciting progress has been made, how to use metasurfaces to realize basic quantum logic gates, such as quantum CZ gates, remains an urgent problem to be solved.
In the research team's previous research, it was found that a single-chip geometric phase gradient metasurface can function similarly to a parallel array of beam splitters, i.e., parallel beam splitting. In this work, the multi-photon interference capability provided by metasurface parallel beam splitting was further utilized. By reasonably designing the beam splitting ratio and selecting three adjacent circularly polarized beam splitting processes, a polarization-encoded CZ gate was successfully constructed on a single metasurface [as shown in Figure 2(a) ].
Because the parallel beam splitting processes of the metasurface are relatively independent and have the ability to work in parallel, using the remaining path-polarization modes supported by the metasurface for photonic qubit encoding, a path-encoded CZ gate can be implemented on the same metasurface [as shown in Figure 2(b) ], as well as multiple independently operating polarization or path-encoded CZ gates. In addition, the characteristic that adjacent beam splitting processes on the metasurface share the same path can be used to cascade two CZ gates, directly constructing a simple three-bit operational quantum circuit on the metasurface[ Figure 2(c) ]。
The metasurface quantum CZ gate not only performs quantum logic functions but also has a certain quantum error filtering capability. In the path encoding case, because the metasurface provides path-polarization correlation characteristics, each qubit is encoded by two correlated degrees of freedom. By detecting the path-polarization correlation characteristics of single photons, some bit-flip errors can be filtered out.
Applications and Prospects
This research provides new ideas for the integration of ultra-compact on-chip quantum logic devices. Multiple quantum CZ gates can be parallelized and simple quantum circuits can be directly constructed using a single metasurface, providing theoretical guidance for multi-functional integration on a single device. Further combining quantum logic operations with the multi-freedom correlation control capabilities of metasurfaces is expected to realize the preparation of high-dimensional entangled states, quantum error detection, and quantum error correction based on metasurfaces, opening up new avenues for quantum information integration based on metasurfaces.
LATEST NEWS
2025-07-12
Hyperspectral channel density on-chip diffractive speckle spectrometer
Driven by the demand for high-performance miniature spectrometers, research on chip-scale spectrometers is continuously breaking through towards high integration, high resolution, and large bandwidth. This work proposes a silicon-based on-chip spectrometer based on cascaded disordered metasurfaces. Through various on-chip wavefront modulation mechanisms, high-spectral speckle is generated, which expands the number of spectral channels with a compact chip size, thus achieving extremely high on-chip spectral channel density and providing an effective means for achieving high-resolution, large-bandwidth spectral detection.
2025-07-14
Ultrasensitive room-temperature extreme photoelectric response achieved
This study, for the first time, achieved the control of ultra-sensitive photoelectric response optimized for room temperature conditions through electromagnetically induced potential well effects and exciton insulator phase transition characteristics.
2025-07-15
Preparation and research progress of glass scintillators for X-ray imaging
Developing suitable host materials with strong X-ray absorption coefficient, good exciton transport efficiency, low phonon energy, and high lanthanide ion solubility remains a cutting-edge research direction in the field of X-ray detection.
2025-07-16
Quantum logic gates based on single-piece gradient metasurface
In today's rapidly developing quantum information technology, realizing efficient and highly integrated quantum logic gates is one of the key challenges in the field of integrated quantum optics.
2025-07-17
Preparation and performance study of epoxy-thiol high-contrast color polymer dispersed liquid crystals
Polymer Dispersed Liquid Crystal (PDLC) is a smart material consisting of micron-sized liquid crystal droplets dispersed in a polymer matrix.
Thank you for visiting the official website of Chongfan Technology. If you have cooperation intentions or suggestions, please contact us through the following methods, and we will reply as soon as possible, thank you!
Address: Room 403, Building 6, Phase III of R&D, No. 36 Xiyong Avenue, High tech Zone, Chongqing, China.
Telephone: +86-13658337211
E-mail: Sales@cfkeji.net
Website: www.cfkeji.net
Mobile Version
