Could the theories with hidden variables be employed for creation of a quantum computer? A particular scheme of quasiclassical model quantum computer structure is describe.
This paper presents a novel theoretical model for quantum decoherence based on topological hidden-variable field theory. The core claim is to establish a model that elucidates the physical mechanism of quantum decoherence and offers a new theoretical foundation for research into quantum computation's resilience against decoherence. We posit that quantum decoherence can be viewed as an emergent phenomenon arising from interactions mediated by hidden variables within a topological hidden-variable field structure. The model utilizes mathematical tools derived from topological hidden-variable field theory to formulate and analyze the underlying physical processes. We demonstrate how the topological nature of the hidden-variable fields influences the decoherence process, providing a fresh perspective on this fundamental challenge in quantum information science. The model aims to bridge the gap between quantum mechanics and topological physics, potentially leading to innovative strategies for mitigating decoherence in quantum computing systems. Key parameters and variables are defined within the model, and the theoretical framework is presented with a focus on providing a conceptual understanding of the decoherence mechanism.
Frustrated spin models may lead to the formation of both classical noncollinear spin structures and unique quantum phases including highly entangled quantum spin liquids. Here, we study the entanglement and spatial quantum correlations in linear spin-wave theory around a classical spin spiral ground state. We find that the entanglement between pairs of sites is short-ranged, and is completely absent in certain cases. In contrast, the entanglement hidden in multisite clusters is peaked close to phase transitions and shows an asymptotic behavior modulated by the period of the magnetic structure. These findings motivate further exploring the connection in the entanglement properties of fully quantum and of quasiclassical spin models.
This paper initiates the study of hidden variables from a quantum computing perspective. For us, a hidden-variable theory is simply a way to convert a unitary matrix that maps one quantum state to another into a stochastic matrix that maps the initial probability distribution to the final one in some fixed basis. We list five axioms that we might want such a theory to satisfy and then investigate which of the axioms can be satisfied simultaneously. Toward this end, we propose a new hidden-variable theory based on network flows. In a second part of the paper, we show that if we could examine the entire history of a hidden variable, then we could efficiently solve problems that are believed to be intractable even for quantum computers. In particular, under any hidden-variable theory satisfying a reasonable axiom, we could solve the graph isomorphism problem in polynomial time, and could search an N-item database using O(N1∕3) queries, as opposed to O(N1∕2) queries with Grover's search algorithm. On the other hand, the N1∕3 bound is optimal, meaning that we could probably not solve NP-complete problems in polynomial time. We thus obtain the first good example of a model of computation that appears slightly more powerful than the quantum computing model.