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Deep Sequence Modeling with Quantum Dynamics: Language as a Wave Function

arXiv:2602.22255v1 Announce Type: new Abstract: We introduce a sequence modeling framework in which the latent state is a complex-valued wave function evolving on a finite-dimensional Hilbert space under a learned, time-dependent Hamiltonian. Unlike standard recurrent architectures that rely on gating mechanisms to suppress competing hypotheses, our framework utilizes quantum interference: the Hamiltonian steers the phases of complex amplitudes so that conflicting interpretations cancel while compatible ones reinforce. The dynamics are strictly unitary, ensuring that the state norm is preserved exactly at every time step via a Cayley (Crank--Nicolson) discretization. Token probabilities are extracted using the Born rule, a quadratic measurement operator that couples magnitudes and relative phases. Our primary theoretical contribution is a separation theorem characterizing the representational advantage of this readout: we define a family of disambiguation tasks that a complex unitary

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Ahmed Nebli, Hadi Saadatdoorabi, Kevin Yam
· · 1 min read · 7 views

arXiv:2602.22255v1 Announce Type: new Abstract: We introduce a sequence modeling framework in which the latent state is a complex-valued wave function evolving on a finite-dimensional Hilbert space under a learned, time-dependent Hamiltonian. Unlike standard recurrent architectures that rely on gating mechanisms to suppress competing hypotheses, our framework utilizes quantum interference: the Hamiltonian steers the phases of complex amplitudes so that conflicting interpretations cancel while compatible ones reinforce. The dynamics are strictly unitary, ensuring that the state norm is preserved exactly at every time step via a Cayley (Crank--Nicolson) discretization. Token probabilities are extracted using the Born rule, a quadratic measurement operator that couples magnitudes and relative phases. Our primary theoretical contribution is a separation theorem characterizing the representational advantage of this readout: we define a family of disambiguation tasks that a complex unitary model of dimension $N$ solves exactly, but which requires a state dimension of $\Omega(N^2)$ for any real-valued orthogonal model equipped with a standard affine-softmax readout. This quadratic gap arises because the Born rule implicitly lifts the $N$-dimensional state into the space of rank-one Hermitian matrices, accessing pairwise phase correlations that are inaccessible to linear projections. Finally, we derive a continuity equation for the latent probability mass, yielding conserved pairwise currents that serve as a built-in diagnostic for tracing information flow between dimensions.

Executive Summary

This article introduces a novel sequence modeling framework inspired by quantum mechanics, where the latent state is represented as a complex-valued wave function evolving under a learned Hamiltonian. The framework leverages quantum interference and unitary dynamics to improve representational capacity, achieving quadratic gap in disambiguation tasks compared to traditional real-valued models. The authors also derive a continuity equation and conserved pairwise currents for tracing information flow. This work has significant implications for sequence modeling and machine learning, potentially enabling more accurate and efficient models for natural language processing and other applications.

Key Points

  • The proposed framework represents the latent state as a complex-valued wave function under a learned, time-dependent Hamiltonian.
  • Quantum interference is used to improve representational capacity, rather than relying on gating mechanisms.
  • The framework achieves quadratic gap in disambiguation tasks compared to traditional real-valued models.
  • A continuity equation is derived, providing conserved pairwise currents for tracing information flow.

Merits

Strength in theoretical contribution

The article provides a novel and well-motivated framework for sequence modeling, with a clear theoretical contribution in the form of a separation theorem and a derived continuity equation.

Potential for improved model performance

The framework's ability to leverage quantum interference and unitary dynamics could lead to improved representational capacity and more accurate models for natural language processing and other applications.

Demerits

Limitation in practical applications

The framework's reliance on complex-valued wave functions and unitary dynamics may introduce computational complexity and practical challenges in implementation and training.

Need for empirical evaluation

While the article provides a strong theoretical foundation, empirical evaluation of the framework's performance and comparison to existing models is necessary to fully assess its potential and limitations.

Expert Commentary

This article represents a significant contribution to the field of machine learning, leveraging insights from quantum mechanics to improve model performance and representation capacity. The framework's potential to achieve quadratic gap in disambiguation tasks is particularly noteworthy, highlighting the potential for improved model accuracy and efficiency. However, practical challenges in implementation and training may arise from the framework's reliance on complex-valued wave functions and unitary dynamics. Empirical evaluation and comparison to existing models are necessary to fully assess the framework's potential and limitations. The work's implications for sequence modeling and natural language processing are significant, with potential applications in areas such as language translation, text summarization, and dialogue systems.

Recommendations

  • Further empirical evaluation and comparison to existing models are necessary to fully assess the framework's potential and limitations.
  • Investigation into practical challenges and computational complexity associated with the framework's implementation and training is warranted.
  • Exploration of potential applications in areas such as language modeling, information retrieval, and cognitive computing is recommended.

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