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Ignacio Cirac

Chronological feed of everything captured from Ignacio Cirac.

Matrix Product Quantum Channels: Structure, Classification, and Correlation Generation

This paper introduces a framework for Matrix Product Quantum Channels (MPQCs), which are one-dimensional tensor-network descriptions of quantum maps. The authors investigate translation-invariant MPQCs with local purification, demonstrating they produce only short-range correlations and are continuously deformable into one another. The framework extends to channels capable of long-range entanglement, which are implementable in constant depth with measurements and feedforward.

Structured Compiler for Quantum Regular Language States

Quantum state preparation typically relies on general-purpose amplitude vector routines or highly specialized constructions. This work introduces a novel compiler that accepts structured specifications for regular language states (RLS) via regular expressions or deterministic finite automata (DFA). This approach provides predictable resource guarantees and offers a more efficient and scalable solution for generating quantum states, including complements, with a focus on optimizing depth and gate count for various hardware architectures.

Polaron-Polaritons: Hybrid Quasiparticles in Trapped Atom Arrays

Optomechanical forces in subwavelength arrays of trapped atoms induce lattice deformations that modify their optical response. This coupling hybridizes collective atomic excitations (polaritons) with phonons, forming polaron-polaritons. These quasiparticles govern light-matter interactions in such systems, impacting phenomena like subradiant state decay, dark excitation transport, and atomic mirror reflectivity.

Efficient Quantum Simulation of Sparse Fermionic Models by Removing Jordan-Wigner Strings

This paper introduces a novel encoding scheme for simulating sparse, non-local fermionic models on quantum computers. By augmenting physical fermionic modes with auxiliary fermions, the method eliminates Jordan-Wigner strings, which traditionally introduce significant overheads. This approach achieves asymptotically optimal circuit depth for long-time evolution, effectively matching the performance of ideal fermionic hardware for sparse models.

Generalized Canonical Forms for MPS with Boundary Conditions

This paper introduces a generalized canonical form for uniform Matrix Product States (MPS) that incorporates boundary matrices, significantly extending the applicability of analytical MPS frameworks beyond periodic boundary conditions. This new framework allows any such MPS to be represented as a block-invertible matrix product operator acting on algebraic regular language states. The work unifies theoretical foundations for MPS with various boundary conditions, expanding the scope for analytical and classification results in quantum many-body systems.