Triply Magic Conditions for Microwave Transition of Optically Trapped Alkali-Metal Atoms

Abstract

We report the finding of "triply magic" conditions (the doubly magic frequency-intensity conditions of an optical dipole trap plus the magic magnetic field) for the microwave transitions of optically trapped alkali-metal atoms. The differential light shift (DLS) induced by a degenerate two-photon process is adopted to compensate a DLS associated with the one-photon process. Thus, doubly magic conditions for the intensity and frequency of the optical trap beam can be found. Moreover, the DLS decouples from the magnetic field in a linearly polarized optical dipole trap, so that the magic condition of the magnetic field can be applied independently. Therefore, the "triply magic" conditions can be realized simultaneously. We also experimentally demonstrate the doubly magic frequency-intensity conditions as well as the independence of the magnetic field. When the triply magic conditions are fulfilled, the inhomogeneous and homogeneous decoherences for the optically trapped atom will be dramatically suppressed, and the coherence time can be extended significantly.

Ab-initio tree-tensor-network digital twin for quantum computer benchmarking in 2D

“…the open system term introduced with the decay does not favor circuits with shorter total time as one expects for the actual hardware. After the leading contribution of decay from the Rydberg state, the next relevant term stems from the fluctuations around the magic trapping condition [60,61], which lead to decoherence, especially in the case of the GHZ state. In principle, perfect magic trapping is so that all three levels pick up the same phase and dephasing is eliminated.…”

Gate fidelity, dephasing, and ‘magic’ trapping of optically trapped neutral atom

“…Usually, the dephasing time can be measured by the Ramsey interference process. If we only consider the dephasing of an atomic coherent superposition state with specific vibrational quantum number n x , n y , and n z , the Ramsey signal will be [23] w Rmsy n = cos δ n t (17) with δ n the frequency difference between driven field and the atomic transitions and t the free precession time. We have the relation δ n = δ 0 + q=x,y,z n q δ q with δ 0 denotes the frequency difference between driven field and the atomic transition on the ground vibrational state n q = 0.…”

“…The evolution of the states will dephase to each other due to the resulting fluctuations on the energy levels. In order to suppressing the DFS, a series of 'magic' trapping conditions, where the differential energy shift between the fiducial states is immune to the fluctuations, are proposed and experimentally tested [8][9][10][11][12][13][14][15][16][17]. The infidelity of the gate operation can be suppressed from 0.01 [18] to 0.5 × 10 −5 [19].…”

Efficient preparation of 2D defect-free atom arrays with near-fewest sorting-atom moves

“…Bottom-up builded single atom arrays have rapidly developed into a versatile platform for quantum many-body simulation [1][2][3][4], quantum metrology [5,6] and quantum computation [7][8][9][10][11][12]. This is mainly owing to several crucial advantages, besides configurable defect-free atom arrays via atom rearrangement [13][14][15][16][17][18], long coherence time of quantum bits (qubits) well-isolated from environment [5,[19][20][21] and controllable long-range interactions using Rydberg atoms [22][23][24][25]. Since a great amount of quantum science and technology based on assembledatom platforms will strongly benefit from scaling the system size to larger atom numbers such as building an faulttolerant information processor with sufficient logic qubits to solve classical intractable tasks [26,27].…”