Recently, Qike Quantum cooperated with Sun Yat-sen University to achieve the quantum velocity limit (QSL) in an open system created by dissipative lasers using cosmic symmetric trap qubits, and explained theoretically from the perspective of Bloch sphere. The research results were published in the international journal New Journal of Physics on January 23 with the title of "Realizing Quantum Speed Limit in Open System with a PT-Symmetric Trapeped-ion Qubit".
Figure: **Officially announced.
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In recent years, a large number of theoretical studies have been devoted to exploring the fastest evolution speed of open quantum systems. The joint research team reported in **The QSL of a PT-symmetric system in an ion trap with controllable state-dependent dissipative and Hamiltonian diagonal term coupling is the first experimental study.
The team enhanced the interaction of qubits with ambient energy by introducing dissipative lasers into the ion trap to construct PT and antiPT Hamiltonians. In this process, the 171yb+ ions are excited to the excited state and then decay back to the ground state by spontaneous radiation. By adjusting the dissipation intensity, the team observed that the evolution time of the quantum state decreases as the dissipation intensity increases, thus approaching QSL.
Figure - Non-Hermitian state transfer of trap qubits. (a).1 to |0⟩，(b).0 to |1 , and (c).|1 to |The evolutionary time of s is dependent on J. (d).Fidelity of the final states of five different j in (c) obtained from quantum state chromatography.
The team improved the QSL while optimizing the dissipation parameters to ensure high fidelity. The experimental results show that under the Pt symmetric and anti-Pt symmetric Hamiltonians, the evolution time of quantum states becomes shorter, and the fidelity of quantum state evolution is maintained at more than 98%.
This study not only achieved a major breakthrough in theory, but:The related research has been applied in practice on the 50-bit trapped-ion quantum computing machine of Qike Quantum, which provides a new impetus for the practical application and commercialization of quantum computers.
At the same time,The QSL demonstrated in this study provides a new perspective for the realization of optimal quantum control, such as extending a single-qubit non-hermetrical bloch sphere to an n-qubit case, which may contribute to a better understanding of n-qubit gate operations in open quantum systems; QSL under non-Hermitian conditions offers a potential solution for finding new precision measurement methods, close to QSL can enhance the accuracy of quantum measurements in non-Hermitian systems; The exploration of QSL can help solve many problems in open systems, such as whether the acceleration of state transition can also increase the rate of entanglement generation, whether the energy cost of state transition can be minimized by reaching QSL, etc.
As the first trapped-ion quantum computing company in China, Qike Quantum has been focusing on the research, development and operation of products, standards and platforms based on distributed quantum computing and quantum network technology, and exploring the road of industry-university-research integration. The relevant person in charge of Qike Quantum said that the cooperation with Sun Yat-sen University is another "strong alliance" between the school and the enterprise, and the two sides have published a number of articles in internationally renowned journals, and jointly tackled the quantum measurement and control system qusoil.
In the future, Qike Quantum will carry out in-depth cooperation with more universities and R&D institutions in scientific research, academic exchanges, talent training and other links to jointly promote the development of quantum science and technology in China.
About New Journal of Physics
The New Journal of Physics (NJP), co-published by IOP and the German Physical Society, is the first open access journal to publish original research results in various fields of physics. NJP is a leading journal of outstanding scientific excellence, attracting the attention and interest of the global physics community, covering topics such as: quantum physics (including quantum information); Atomic and Molecular Physics; optics, photonics, and device physics; condensed matter; nanoscience; soft matter and polymers; Chemical Physics; statistical mechanics, thermodynamics, and nonlinear systems; fluid dynamics; Plasma; Nuclear and Particle Physics; cosmology and astrophysics; Biological and Medical Physics; Earth sciences and geophysics, among others.