We introduce Present Quantum Gravity (PQG), a novel framework grounded in an informational ontology in which only the present instant exists. The Present is described as a quantum memory updating in discrete ticks, encoding entanglement as closed loop structures in a Wick-rotated, relational space. Building on time-symmetric quantum mechanics, holographic principles and entropic gravity, rest mass is reinterpreted as information hidden through temporal entanglement and gravity emerges from a local symmetry breaking of spatial entanglement to compensate for hidden information. From this informational asymmetry, we recover the Newtonian potential and weak-field gravitational time dilations, interpreted as reductions in accessible degrees of freedom. PQG is conceptually compatible with established interpretations, while providing predictions that are in principle falsifiable. Limitations, such as the absence of a field theoretic dynamics or the full Einstein equations, and research avenues, including connections to Einstein–Cartan theory, are discussed at the end of the paper. This work synthesizes the status of the framework as presented at Quantum2025 (Torino, IT), emphasizing its conceptual advances, experimental proposals and roadmap toward a fully dynamical theory, while leaving the details to the referenced literature.

This paper first demonstrates that by appropriately specifying the evolution interval in quantum partial adiabatic evolution, the time complexity of the resulting quantum search algorithm can achieve the well-known quadratic speedup bound of quantum computation. Then this result is used as a reference to remedy invalid quantum partial adiabatic search schemes, which means its time complexity doesn’t align with the optimal quantum speedup. And, it is found that the two versions of quantum partial adiabatic evolutions, i.e. “global” and “local” ones must be treated separately, despite previous studies indicating only minor differences in algorithmic performance between the two cases. Additionally, for the “local” variant of the quantum partial adiabatic search algorithm, it can be seen that there are other possible choices for the evolution interval besides the referred one. Our findings further show that significant variations in the resulting single-round success probabilities occur between valid and invalid quantum partial adiabatic evolutions.

Twin-Field Quantum Key Distribution (TF-QKD) is a promising protocol to extend the secure communication range beyond the limits of conventional QKD, provided that phase noise along the optical channels is tightly controlled. In this work, we experimentally investigate the electro-mechanical phase noise affecting optical fibers in electrical grid environments, as a preliminary step toward deploying TF-QKD over Optical Ground Wire (OPGW) networks that run together with the electricity grids. Measurements were performed in a medium and low voltage smart grid test facility, which offered an accessible and controllable environment that shares some key features with OPGW installations. We analyze phase noise under varying electrical load conditions and infer the corresponding Quantum Bit Error Rate (QBER), providing a first experimental benchmark for future quantum communication over power grid fibers.

Quantum computation promises exponential speedups over classical algorithms, but current Noisy Intermediate-Scale Quantum (NISQ) devices remain highly susceptible to noise. We introduce a Bell-basis computational framework in which each logical qubit is encoded as an entangled pair whose correlation structure enables intrinsic detectability of correlation-breaking errors. Rather than performing explicit recovery or fault-tolerant correction, the scheme implements an intrinsic verification rule that accepts or discards outcomes based on the preservation of Bell-type correlations. A universal logical gate set acting natively in the Bell basis is derived, and Qiskit simulations confirm that correlation violations can be detected with rates of 4–6% under realistic depolarizing and amplitude-damping noise. This approach provides a postselection-based pathway toward verifiable quantum computation on near-term hardware, offering a pragmatic complement to full quantum error correction.

In this paper, we investigate spin entanglement dynamics in the tree-level QED scattering processes [Formula: see text] and [Formula: see text]. By exploiting the complete complementarity relations, we highlight the interplay among entanglement, predictability and visibility mediated by the fundamental interaction, for different energy regimes.

In this paper, we analyze a quantum heat engine described by the full Dicke model. The system exhibits quantum phase transitions under certain conditions. We consider the system performing a Stirling thermodynamic cycle. We obtain an enhancement of efficiency when during the cycle the coupling parameter crosses a critical value. We analyze the effect of unbalance between rotating and counter-rotating terms in the model. The maximum efficiency is obtained when the contributions of the counter-rotating and rotating terms are equal. The relation between ground state degeneracy, related to the quantum phase transition and maximum efficiency is investigated.

Implementing a digital Earth requires processing an enormous amount of data. Compared with classical algorithms, quantum algorithms can take exponential or quadratic acceleration and are more suitable for processing big data. However, existing quantum models require massive resources to process data on the Earth due to their low compatibility with spheres. So, we propose a quantum representation of the Earth based on the Bloch sphere (QREB), which is tailor-made for the Earth. Based on this model, the scale transformation and specific rotation transformation only need to change one variable. And the time complexity of the quantum point of interest extraction algorithm based on this model is the square root of the classical algorithm. Moreover, in the example of extracting thin black lines on the basketball, the accuracy is improved from 50% to 87.5%. The QREB model can reduce the resources required to process spherical data and accelerate the realization of a digital Earth.

Blind quantum computation (for measuring the client Alice) protocol changes the role of the client from state preparation to measurement. In order to further save the quantum cost and delegated cost of Alice, two protocols are proposed to complete a certain single-qubit gate with fewer measurements and qubits while remaining loss tolerant in this paper. Finally, the protocols are feasibility from three aspects: blindness, correctness and universality.

In this paper, we propose a new quantum signature protocol with identity-based threshold multiple verifiers. In this protocol, first, the signature process combines the HMAC hash function with the participant identity to realize the compression encryption of the signature message, at the same time, the signature particles are encoded and generated by selecting the 3-particle GHZ state of the [Formula: see text] spatially localizable distinguished (LOCC), which avoids the complex entanglement operation and effectively improves the signature efficiency; second, it takes at least t verifying members of the set of valid verifications specified by the signer to verify the validity of the final signature, which increases the utility of the signature protocol in multi-verification scenarios; finally, the security analysis shows that the proposed threshold multiparty verifiable quantum signature protocol scheme can resist entanglement measurement attacks, intercept retransmission attacks, and at the same time be unforgeable, nonrepudiable, and traceable. Most importantly, the protocol does not require Quantum One-Way Function (QOWF), Quantum State Swap Test (SWAP), and has no complex entanglement operations. Therefore, the proposed scheme is more efficient than similar multiparty signature protocols.

In this paper, we present a new and algebraically simple algorithm that prepares any pure three-qubit state using only local gates and at most three controlled-[Formula: see text] gates. In 2008, Znidaric et al. already showed that three is the optimal number of controlled-[Formula: see text] gates required for the preparation of three-qubit states if in addition to those gates only local gates are used. If we restrict the local gates to [Formula: see text] gates, our algorithm provides a way to prepare any pure three-qubit state [Formula: see text] with real amplitudes using at most four controlled-[Formula: see text] gates when its hyperdeterminant is negative and three or fewer controlled-[Formula: see text] gates otherwise. We conjecture the existence of three-qubit states with real amplitudes that cannot be prepared using only [Formula: see text] gates and less than four controlled-[Formula: see text] gates.