Time-Domain Grating with a Periodically Driven Qutrit

Abstract

Physical systems in the time domain may exhibit analogous phenomena in real space, such as time crystals, time-domain Fresnel lenses, and modulational interference in a qubit. Here we report the experimental realization of time-domain grating using a superconducting qutrit in periodically modulated probe and control fields via two schemes: Simultaneous modulation and complementary modulation. Both experimental and numerical results exhibit modulated Autler-Townes (AT) and modulation-induced diffraction (MID) effects. Theoretical results also confirm that the peak positions of the interference fringes of AT and MID effects are determined by the usual two-level relative phases, while the observed diffraction fringes, appearing only in the complementary modulation, are however related to the three-level relative phase. Further analysis indicates that such a single-atom time-domain diffraction originates from the correlation effect between the two time-domain gratings. Moreover, we find that the widths of the diffraction fringes are independent of the control-field power. Our results shed light on the experimental exploration of quantum coherence for modulated multilevel systems and may find promising applications in fast all-microwave switches and quantum-gate operations in the strong-driving regime.I.

Quantum information dynamics in a high-dimensional parity-time-symmetric system

“…This PT -symmetry-breaking transition occurs at an EP of order n (EPn), where n eigenvalues, as well as their corresponding eigenvectors, coalesce [17][18][19]. The PT transition and the non-unitary time evolution generated by H PT have been observed in classical systems with EP2 [6][7][8][9][10][11][12][13][14][20][21][22][23][24][25][26], EP3 [15], and higher order EPs [27,28].…”

Implementing a multi-target-qubit controlled-not gate with logical qubits outside a decoherence-free subspace and its application in creating quantum entangled states

“…This gate is implemented by employing qutrits (three-level quantum systems) placed in a cavity or coupled to a resonator. In the past, much attention has been paid on quantum operations with qutrits or qudits [48][49][50][51] As shown below, this proposal has these advantages: (i) The states of the logical qubits return to the DFS after the gate operation, (ii) The gate can be implemented with only a few basic operations; (iii) The gate operation time is independent of the number of logical qubits and thus does not increase with the number of logical qubits; (iv) this gate can be implemented in a deterministic way because no measurement on the state of the qutrits or the cavity is needed; and (v) The intermediate higher energy level |2 for all qutrits is not occupied during the entire operation, thus decoherence from this level is greatly suppressed. Moreover, this proposal is universal and can be applied to realize the proposed gate using natural atoms or artificial atoms (e.g., quantum dots, NV centers, and various superconducting qutrits, etc.)…”

Higher‐Order Nonclassicality in Photon Added and Subtracted Qudit States

“…The number of such successful experiments are small compared to experiments involving qubits, but the experiments are related to various aspects of physics including but not restricted to superconducting phase qudit, [28] quantum football, [29] quantum state tomography of large nuclear spin, [30] and time-domain grating with a periodically driven qutrit. [31] Above-mentioned techniques in Figure 1a,b can be used to generate engineered quantum states. Interesting examples of such engineered nonclassical states are Fock state, photon added/subtracted coherent state, displaced Fock state, intermediate state like binomial state (BS), and NGBS.…”