Mikel Garcia-de-Andoin, Thorge Müller, Gonzalo Camacho • Published: 2025-11-14
Digital-analog is a quantum computational paradigm that employs the natural interaction Hamiltonian of a system as the entangling resource, combined with single qubit gates, to implement universal quantum operations. As in the case of its digital gate-based counterpart, designing digital-analog circuits that employ optimal quantum resources often requires an exceedingly large classical computation...
Fabian Wiesner, Anna Pappa • Published: 2026-03-10
Delegated quantum computation enables a client with limited quantum capabilities to outsource computations to a more powerful quantum server while preserving correctness and privacy. Verification is crucial in this setting to ensure that the untrusted quantum server performs the computation honestly and returns correct results. A common verification method is the quantum cut-and-choose technique. ...
Xi Lu, Bojko N. Bakalov, Yuan Liu • Published: 2026-03-10
We introduce a framework for simulating hybrid oscillator-qubit quantum processors on qubit-only systems through position encoding. By encoding continuous-variable position and momentum wave functions into qubit amplitudes, our method efficiently simulates all Gaussian and conditional Gaussian operations -- encompassing the phase-space instruction set (beam splitter, single-qubit rotation, conditi...
Prince Frederick Kwao, Srivathsan Poyyapakkam Sundar, Brajesh Gupt, Ayush Asthana • Published: 2025-03-12
Solving challenging problems in quantum chemistry is one of the most promising applications of quantum computers. Within the quantum algorithms proposed for problems in excited state quantum chemistry, subspace-based quantum algorithms, including quantum subspace expansion (QSE), quantum equation of motion (qEOM) and quantum self-consistent equation-of-motion (q-sc-EOM), are promising for pre-faul...
Arturo Acuaviva, David Aguirre, Rubén Peña, Mikel Sanz • Published: 2024-07-15
The technological development of increasingly larger quantum processors on different quantum platforms raises the problem of how to fairly compare their performance, known as quantum benchmarking of quantum processors. This is a challenge that computer scientists have already faced when comparing classical processors, leading to the development of various mathematical tools to address it, but also...
Samuele Piccinelli, Stefano Barison, Alberto Baiardi, Francesco Tacchino, Jascha Repp, Igor Rončević, Florian Albrecht, Harry L. Anderson, Leo Gross, Alessandro Curioni, Ivano Tavernelli • Published: 2026-03-09
We report quantum chemistry calculations performed on superconducting quantum processors for a molecule exhibiting the half-Möbius electronic topology originally introduced by Rončević et al. Using SqDRIFT, a randomized sample-based Krylov quantum diagonalization algorithm, we achieve reliable quantum simulations on active spaces corresponding to 36 orbitals (72 qubits) and extend previous studies...
Alessandro Cosentino, Changhao Li, Vincent Russo, Bradley A. Chase, Tom Lubinski, Siyuan Niu, Neer Patel, Nathan Shammah, William J. Zeng • Published: 2026-03-09
The fragmented landscape of quantum computer benchmarks, characterized by system-specific tools and inconsistent evaluation methodologies, hinders reliable cross-platform performance assessment. We introduce Metriq, an open-source collaborative platform for reproducible cross-platform quantum benchmarking that integrates benchmark definition and execution, data collection, and public presentation ...
Mikel Garcia-de-Andoin, Alatz Álvarez-Ahedo, Adrián Franco-Rubio, Mikel Sanz • Published: 2025-05-06
Digital-analog is a universal quantum computing paradigm which employs the natural entangling Hamiltonian of the system and single-qubit gates as resources. Here, we study the stability of these protocols against Hamiltonian characterization errors. For this, we bound the maximum separation between the target and the implemented Hamiltonians. Additionally, we obtain an upper bound for the deviatio...
Baptiste Claudon, Sergi Ramos-Calderer, Jean-Philip Piquemal • Published: 2026-03-09
Quantum algorithms present a quadratically improved complexity over classical ones for certain sampling tasks. For instance, the Quantum Amplitude Estimation (QAE) algorithm promises to speedup the estimation of the mean of certain functions, given access to the quantum state corresponding to the probability distribution to be sampled from. Classically, samples are often obtained by running steps ...
Kyoungho Cho, Ilkwon Sohn, Yongsoo Hwang, Jeongho Bang • Published: 2026-03-08
Gate fidelity -- an average fidelity over all possible input states -- is the workhorse metric for benchmarking quantum gates or circuits, yet fault-tolerant quantum computing ultimately depends on the worst-case behavior, typically quantifiable by so-called the diamond distance. In the low-error regime, the coherent errors can inflate the worst-case error even when the reported gate fidelity is h...