Besides noticeable challenges in implementing low-error single- and two-qubit quantum gates in superconducting quantum processors, the readout technique and analysis are a key factor in determining the efficiency and performance of quantum processors. Being able to efficiently implement quantum algorithms involving entangling gates and asses their output is mandatory for quantum utility. In a transmon-based 5-qubit superconducting quantum processor, we compared the performance of quantum circuits involving an increasing level of complexity, from single-qubit circuits to maximally entangled Bell circuits. This comparison highlighted the importance of the readout analysis and helped us optimize the protocol for more advanced quantum algorithms. Here, we report the results obtained from the analysis of the outputs of quantum circuits using two readout paradigms, referred to as “multiplied readout probabilities” and “conditional readout probabilities.” The first method is suitable for single-qubit circuits, while the second is essential for accurately interpreting the outputs of circuits involving two-qubit gates.
Quantum simulations offer opportunities both for studying many-body physics and for generating useful entangled states. However, existing platforms are usually restricted to specific types of interaction, fundamentally limiting the models they can mimic. Here we realize an all-to-all interacting model with an arbitrary quadratic Hamiltonian, thus demonstrating an infinite-range tunable Heisenberg XYZ model. This was accomplished by engineering cavity-mediated four-photon interactions between an ensemble of 700 rubidium atoms with a pair of momentum states serving as the effective qubit degree of freedom. As one example of the versatility of this approach, we implemented the so-called two-axis counter-twisting model, a collective spin model that can generate spin-squeezed states that saturate the Heisenberg limit on quantum phase estimation. Furthermore, our platform allows for including more than two relevant momentum states by simply adding additional dressing laser tones. This approach opens opportunities for quantum simulation and quantum sensing with matter–wave interferometers and other quantum sensors, such as optical clocks and magnetometers.
We investigate marginally outer trapped surfaces (MOTS) (Sigma ^2) within a three-dimensional initial data set (M^3), devoid of charge density, for the Einstein–Maxwell equations in the absence of a magnetic field and with a cosmological constant (Lambda ). Assuming (Sigma ) to be a stable MOTS with genus (g(Sigma )), we derive an inequality that relates the area of (Sigma ), (g(Sigma )), (Lambda ), and the charge (q(Sigma )) of (Sigma ). In cases where equality is achieved, we demonstrate local splitting of M along (Sigma ). Specifically, in the scenario where (Lambda >0), we establish that (Sigma ) forms a round 2-sphere. These findings extend the theorems of Galloway and Mendes to initial data sets featuring an electric field. Moreover, for (Lambda >0), we additionally demonstrate that these initial data sets can be locally embedded as spacelike hypersurfaces within the Charged Nariai spacetime.
The modified Zakharov-Kuznetsov equation for ion-acoustic waves was developed using the reductive perturbation method in a multi-ion plasma system consisting of inertial ions that are both negatively and positively charged, as well as positively charged immobile heavy ions and electrons that are trapped in the presence of a quantizing magnetic field. Depending on the system’s characteristics, we looked at bifurcation analysis. All conceivable phase pictures, including periodic, homoclinic, and superperiodic trajectories, are shown. The occurrence of rarefactive and compressive solitary waves is demonstrated. The finite degenerate temperature, polarization parameter, and plasma particle number densities, charges, and masses all substantially influence these solitons. Furthermore, the plasma system under investigation might accommodate both nonlinear and superlinear periodic waves. The current discoveries are thought to be useful in comprehending the solitary structures in dense quantum plasmas like those seen in white dwarfs.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：