arXiv subjects

Carlos Ramos Marimón

Publications and source records attributed to Carlos Ramos Marimón.

4 recordsLinked to original sources

arXiv2026

Measuring temporal entropies in experiments

We propose a novel experimental protocol to measure generalized temporal entropies in many-body quantum systems. Our approach involves using local operators as probes to characterize the out-of-equilibrium dynamics induced by a geometric double quench on a replicated system. Such protocol mimics the path-integral on the corresponding Riemann surface encoding generalized temporal entanglement. We present the results of tensor network simulations of one-dimensional systems which validate the protocol and demonstrate the experimental feasibility of measuring generalized temporal entropies, and we outline the experimental requirements for implementing these quenches using state-of-the-art quantum simulators. Therefore, our results provide a physical interpretation of the meaning of generalized temporal entropies. Furthermore, they reveal that the dynamics induced on two replicas of the Ising model in a transverse field differ qualitatively from the ones of its non-integrable extension, suggesting that generalized temporal entropies can be used as a tool for identifying different dynamical classes in quantum systems.

quant-ph↗

arXiv2026

The SpinPulse library for transpilation and noise-accurate simulation of spin qubit quantum computers

We introduce SpinPulse, an open-source python package for simulating spin qubit-based quantum computers at the pulse-level. SpinPulse models the specific physics of spin qubits, particularly through the inclusion of classical non-Markovian noise. This enables realistic simulations of native gates and quantum circuits, in order to support hardware development. In SpinPulse, a quantum circuit is first transpiled into the native gate set of our model and then converted to a pulse sequence. This pulse sequence is subsequently integrated numerically in the presence of a simulated noisy experimental environment. We showcase workflows including transpilation, pulse-level compilation, hardware benchmarking, quantum error mitigation, and large-scale simulations via integration with the tensor-network library quimb. We expect SpinPulse to be a valuable open-source tool for the quantum computing community, fostering efforts to devise high-fidelity quantum circuits and improved strategies for quantum error mitigation and correction.

quant-ph↗

arXiv2024

On temporal entropy and the complexity of computing the expectation value of local operators after a quench

We study the computational complexity of simulating the time-dependent expectation value of a local operator in a one-dimensional quantum system by using temporal matrix product states. We argue that such cost is intimately related to that of encoding temporal transition matrices and their partial traces. In particular, we show that we can upper-bound the rank of these reduced transition matrices by the one of the Heisenberg evolution of local operators, thus making connection between two apparently different quantities, the temporal entanglement and the local operator entanglement. As a result, whenever the local operator entanglement grows slower than linearly in time, we show that computing time-dependent expectation values of local operators using temporal matrix product states is likely advantageous with respect to computing the same quantities using standard matrix product states techniques.

cond-mat.stat-mech↗

arXiv2023

Transition from acoustic plasmon to electronic sound in graphene

Fermi liquids respond differently to perturbations depending on whether their frequency is larger (collisionless regime) or smaller (hydrodynamic regime) than the inter-particle collision rate. This results in a different phase velocity between the collisionless zero sound and hydrodynamic first sound. We performed terahertz photocurrent nanoscopy measurements on graphene devices, with a metallic gate in close proximity to the sample, to probe the dispersion of propagating acoustic plasmons, the counterpart of sound modes in electronic Fermi liquids. We report the observation of a change in the plasmon phase velocity when the excitation frequency approaches the electron-electron collision rate. This first observation of the first sound mode in an electronic Fermi liquid is of fundamental interest and can enable novel terahertz emitter and detection implementations.

cond-mat.mes-hall↗