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Haiqing Wei

Publications and source records attributed to Haiqing Wei.

18 recordsLinked to original sources
arXiv2026

The quantum pigeonhole effect as a new form of Bell's theorem without inequality

The quantum pigeonhole effect (QPE) appears to contradict the classical pigeonhole principle by allowing three quantum particles distributed between two boxes to exhibit no pairwise coincidence. We show that this effect does not signal a breakdown of classical counting, but instead arises from quantum contextuality. By deriving Bell-type inequalities directly from the pigeonhole principle and reformulating the weak-measurement protocol within a bipartite density-operator framework, we demonstrate that the QPE is a form of Bell's theorem without inequalities. The apparent paradox reflects the impossibility of non-contextual eigenvalue assignments rather than a violation of classical combinatorial logic.

quant-ph↗
arXiv2018

Comment on "All-optical machine learning using diffractive deep neural networks"

Lin et al. (Reports, 7 September 2018, p. 1004) reported a remarkable proposal that employs a passive, strictly linear optical setup to perform pattern classifications. But interpreting the multilayer diffractive setup as a deep neural network and advocating it as an all-optical deep learning framework are not well justified and represent a mischaracterization of the system by overlooking its defining characteristics of perfect linearity and strict passivity.

cs.LG↗
arXiv2013

Trapping Quantum Coherence in Local Energy Minima

Clusters of solid-state quantum devices have long-living metastable states of local energy minima which may be used to store quantum information. The low to vanishing rate of dissipation fulfils the prerequisite to maintain quantum coherence. Then physical symmetrization of the devices could minimize the couplings of the clusters to environmental degrees of freedom so to reduce the rate of decoherence. Combined with various other error correction mechanisms and methods, such designs and optimizations could render solid-state devices useful for quantum information processing, which have the advantages of flexibility in state manipulation and system scaling.

quant-ph↗
arXiv2010

Fundamental Limits of "Ankylography" due to Dimensional Deficiency

Single-shot diffractive imaging of truly 3D structures suffers from a dimensional deficiency and does not scale. The applicability of "ankylography" is limited to objects that are small-sized in at least one dimension or that are essentially 2D otherwise.

physics.optics↗
arXiv2006

Collective Shape-Phases of Interacting Fermion Systems

A microscopic theory is presented for identifying shape-phase structures and transitions in interacting fermion systems. The method provides a microscopic description for collective shape-phases, and reveals detailed dependence of such shape-phases on microscopic interaction strengths. The theory is generally applicable to fermion systems such as nuclei, quarks, and in particular trapped cold atoms, where shape-phases may be observed and investigated in a controlled manner.

nucl-th↗
arXiv2006

Approach to the Rotation Driven Vibrational to Axially Rotational Shape Phase Transition Along the Yrast Line of a Nucleus

By analyzing the potential energy surface, the shape phase diagram and the energy spectrum of the nucleus in U(5) symmetry in the IBM, we propose that the U(5) symmetry with parameters $(A+B) < 0$ may be a model to describe the rotation driven vibrational to axially rotational phase transition along the yrast line. With such a model, we have described successfully the observed rotation driven shape phase transition along the yrast line of individual nucleus and proposed some other empirical evidences.

nucl-th↗
arXiv2004

Dynamic Models and Nonlinear Filtering of Wave Propagation in Random Fields

In this paper, a general model of wireless channels is established based on the physics of wave propagation. Then the problems of inverse scattering and channel prediction are formulated as nonlinear filtering problems. The solutions to the nonlinear filtering problems are given in the form of dynamic evolution equations of the estimated quantities. Finally, examples are provided to illustrate the practical applications of the proposed theory.

physics.data-an↗
arXiv2003

On the Capacity of Nonlinear Fiber Channels

The nonlinearity of a transmission fiber may be compensated by a specialty fiber and an optical phase conjugator. Such combination may be used to pre-distort signals before each fiber span so to linearize an entire transmission line.

physics.optics↗
arXiv1998

Single Molecule Magnetic Resonance and Quantum Computation

It is proposed that nuclear (or electron) spins in a trapped molecule would be well isolated from the environment and the state of each spin can be measured by means of mechanical detection of magnetic resonance. Therefore molecular traps make an entirely new approach possible for spin-resonance quantum computation which can be conveniently scaled up. In the context of magnetic resonance spectroscopy, a molecular trap promises the ultimate sensitivity for single spin detection and an unprecedented spectral resolution as well.

quant-ph↗
arXiv1998

NMR Quantum Automata in Doped Crystals

In a lattice ${\cal L}$ of nuclear spins with ABCABCABC... type periodic structure embedded in a single-crystal solid, each ABC-unit can be used to store quantum information and the information can be moved around via some cellular shifting mechanism. Impurity doping marks a special site D$\not\in{\cal L}$ which together with the local spin lattice constitute a quantum automaton where the D site serves as the input/output port and universal quantum logic is done through two-body interactions between two spins at D and a nearby site. The novel NMR quantum computer can be easily scaled up and may work at low temperature to overcome the problem of exponential decay in signal-to-noise ratio in room temperature NMR.

quant-ph↗
arXiv1998

Quantum Isomorphic Simulation

A new type of quantum simulator is proposed which can simulate any quantum many-body system in an isomorphic manner. It can actually synthesize a duplicate of the system to be simulated. The isomorphic simulation has the great advantage that the inevitable coupling of the simulator to the environment can be fully exploited in simulating thermodynamic processes.

quant-ph↗
arXiv1998

Static Quantum Computation

Tailoring many-body interactions among a proper quantum system endows it with computing ability by means of static quantum computation in the sense that some of the physical degrees of freedom can be used to store binary information and the corresponding binary variables satisfy some given logic relations if and only if the system is in the ground state. Two theorems are proved showing that the universal static quantum computer can encode the solutions for any P and NP problem into its ground state using only polynomial number (in the problem input size) of logic gates. The second step is to read out the solutions by relaxing the system. The time complexity is relevant when one tries to read out the solution by relaxing the system, therefore our model of static quantum computation provides a new connection between the computational complexity and the dynamics of a complex system.

quant-ph↗
arXiv1997

Tailoring Many-Body Interactions to Solve Hard Combinatorial Problems

A quantum machine consisting of interacting linear clusters of atoms is proposed for the 3SAT problem. Each cluster with two relevant states of collective motion can be used to register a Boolean variable. Given any 3SAT Boolean formula the interactions among the clusters can be so tailored that the ground state(s) (possibly degenerate) of the whole system encodes the satisfying truth assignment(s) for it. This relates the 3SAT problem to the dynamics of the properly designed glass system.

quant-ph↗
arXiv1997

Superconductive Static Quantum Logic

Superconducting rings with exactly $Φ_0/2$ magnetic flux threading are analogous of Ising spins having two degenerate states which can be used to store binary information. When brought close these rings interact by means of magnetic coupling. If the interactions are properly tailored, a system of such superconducting rings can accomplish static quantum logic in the sense that the states of the rings interpreted as Boolean variables satisfy the desired logic relations when and only when the whole system is in the ground state. Such static logic is essential to carry out the static quantum computation [1,2].

quant-ph↗