时间：2024年10月14日星期一 16:00-17:20
地点：九龙湖校区田家炳楼南203 平星报告厅
主持人：薛鹏 教授
报告一：Superconducting quantum circuits at RQC
报告人：Alexey Ustinov, PI of the Superconducting Qubits and Quantum Circuits group, Russian Quantum Center
摘要：Russian Quantum Center was the first laboratory in Russia that initiated experiments with superconducting qubits. We measured our first qubits back in 2015 and established collaborations towards the research on quantum circuits with three major universities in Moscow area. Our current research directions involve a scalable architecture of quantum processors, the design of quantum simulators, and the creation of quantum metamaterials. The spectrum of our interests extends from high-fidelity quantum gates to implementation of quantum error correction protocols. In the talk I will review some of our recent results and describe the infrastructure.
报告二：Ultra-high-Q optical microresonators and their application in nonlinear and quantum optics
报告人：Igor Bilenko, PI of the Coherent Microoptics and Radiophotonics group, Russian Quantum Center
摘要：Ultra-high-Q (WGM) microresonators are currently used in a wide range of applications, including narrow-band lasers, high-sensitivity sensors, and frequency comb sources. Moreover, they are unique photonic devices that provide extreme conditions for light storage, enabling the observation of many unconventional nonlinear and quantum optical phenomena. Although various materials and methods are already used to fabricate high-Q resonators, finding new ones is important to extend their application to mid-IR wavelengths and to integrate them with electronic devices. We present our latest results obtained with promising materials such as Ge, Si, and GaAs.
The auto- and cross-phase modulations that occur in microresonators with Kerr nonlinearity allow the implementation of purely quantum effects. We demonstrate that even with single-frequency pumping, it is possible to form a state characterized by a non-Gaussian distribution with negative Wigner function values — a purely non-classical state of light. Its interaction with a weak signal in the resonator can enable quantum non-demolishing (QND) measurements. When two resonant waves are injected into the resonator, degenerate four-wave mixing can lead to parametric oscillations at an intermediate wavelength, which essentially represent Schrödinger cat states and can be used to build the so-called coherent Ising machine — an all-optical solver for various optimization problems. Using such a parametric oscillator based on a chip-scale microresonator fabricated by our Chinese partner, we have already demonstrated optical bistability and quantum squeezing.
报告三：50-qubit ion-based quantum computer using a qudit architecture
报告人：Ilya Semerikov, Junior PI of the Scalable Ion Quantum Computing group, Russian Quantum Center
摘要：In our laboratory, a quantum computer has been developed and manufactured using an optical transition in a ytterbium ion at a wavelength of 435 nm. Currently, 4 Zeeman sublevels are used for encoding information. The report will describe the technical structure of the ion quantum computer, as well as methods for protecting qudit states from decoherence. Additionally, the results of running qudit and qubit quantum algorithms will be presented.
报告四：Optical clock and quantum computing with lanthanides
报告人：Artem Golovizin, Junior PI of the Digital Fermionic Quantum Simulator on Ytterbium Atoms group, Russian Quantum Center
摘要：Ultracold atoms are widely used in fundamental research and applications owing to the incredible level of control over atomic state and their evolution. One great example is optical clocks, which reach 10-18 level of accuracy and instability and are now considered for redefinition of the SI second. Another example is the field of quantum computation and simulation, where one needs to provide a high level of system isolation from the environment with a number of qubits at 1000 or more.
I will present our recent results on building and comparison of two thulium optical clocks, which feature very low blackbody radiation and zeeman shifts of the clock transition frequency. In the second part, I'll discuss our first steps towards development of a quantum simulator and computer based on neutral ytterbium atoms.