Publications related to Quantum operation

Empirical Sample Complexity of Neural Network Mixed State Reconstruction

Giuseppe Carleo, Filippo Vicentini, Haimeng Zhao

Quantum state reconstruction using Neural Quantum States has been proposed as a viable tool to reduce quantum shot complexity in practical applications, and its advantage over competing techniques has been shown in numerical experiments focusing mainly on ...

Verein Forderung Open Access Publizierens Quantenwissenschaf2024

Scalable Quantum Algorithms for Noisy Quantum Computers

Julien Sebastian Gacon

Quantum computing not only holds the potential to solve long-standing problems in quantum physics, but also to offer speed-ups across a broad spectrum of other fields. Access to a computational space that incorporates quantum effects, such as superposition ...

EPFL2024

Large Orbital Moment of Two Coupled Spin-Half Co Ions in a Complex on Gold

Stefano Rusponi, Chao Li, Boris Sorokin

The magnetic propertiesof transition-metal ions aregenerallydescribed by the atomic spins of the ions and their exchange coupling.The orbital moment, usually largely quenched due the ligand field,is then seen as a perturbation. In such a scheme, S = 1/2 io ...

AMER CHEMICAL SOC2023

Unbiasing time-dependent Variational Monte Carlo by projected quantum evolution

Giuseppe Carleo, Clemens Giuliani, Alessandro Sinibaldi, Filippo Vicentini

We analyze the accuracy and sample complexity of variational Monte Carlo approaches to simulate the dynamics of many-body quantum systems classically. By systematically studying the relevant stochastic estimators, we are able to: (i) prove that the most us ...

Verein Forderung Open Access Publizierens Quantenwissenschaf2023

Arnoldi-Lindblad time evolution: Faster-than-the-clock algorithm for the spectrum of time-independent and Floquet open quantum systems

Fabrizio Minganti

The characterization of open quantum systems is a central and recurring problem for the development of quantum technologies. For time-independent systems, an (often unique) steady state describes the average physics once all the transient processes have fa ...

VEREIN FORDERUNG OPEN ACCESS PUBLIZIERENS QUANTENWISSENSCHAF2022

Engineering and characterizing nonclassical states of light in quantum optical networks

Kilian Robert Seibold

The exploration of open quantum many-body systems -systems of microscopic size exhibiting quantum coherence and interacting with their surrounding- has emerged as a key research area over the last years. The recent advances in controlling and preserving qu ...

EPFL2022

Quantum dynamics of dissipative Kerr solitons

Vincenzo Savona, Fabrizio Minganti, Riccardo Rota, Kilian Robert Seibold

Dissipative Kerr solitons arising from parametric gain in ring microresonators are usually described within a classical mean-field framework. Here, we develop a quantum-mechanical model of dissipative Kerr solitons in terms of the Lindblad master equation ...

AMER PHYSICAL SOC2022

Gravitational causality and the self-stress of photons

Brando Bellazzini, Giulia Isabella

We study causality in gravitational systems beyond the classical limit. Using on-shell methods, we consider the 1-loop corrections from charged particles to the photon energy-momentum tensor - the self-stress - that controls the quantum interaction between ...

Springer Nature2022

Simulating the ghost: quantum dynamics of the solvated electron

Michele Ceriotti, Venkat Kapil, Piero Gasparotto, Jinggang Lan

The nature of the bulk hydrated electron has been a challenge for both experiment and theory due to its short lifetime and high reactivity, and the need for a high-level of electronic structure theory to achieve predictive accuracy. The lack of a classical ...

Nature Research2021

Sparsely Observed Functional Time Series: Theory and Applications

Tomas Rubin

Functional time series is a temporally ordered sequence of not necessarily independent random curves. While the statistical analysis of such data has been traditionally carried out under the assumption of completely observed functional data, it may well ha ...

EPFL2021

On-the-Fly ab initio Semiclassical Evaluation of Electronic Coherences in Polyatomic Molecules Reveals a Simple Mechanism of Decoherence

Jiri Vanicek, Tomislav Begusic, Nikolay Golubev

Irradiation of a molecular system by an intense laser field can trigger dynamics of both electronic and nuclear subsystems. The lighter electrons usually move on much faster, attosecond timescale but the slow nuclear rearrangement damps ultrafast electroni ...

2020

Impact of Classical Control Electronics on Qubit Fidelity

Edoardo Charbon, Fabio Sebastiano

Quantum processors rely on classical electronic controllers to manipulate and read out the state of quantum bits (qubits). As the performance of the quantum processor improves, nonidealities in the classical controller can become the performance bottleneck ...

American Physical Society (APS)2019

Fourier dimensionality reduction for fast radio transients

Jean-Philippe Thiran, Yves Wiaux, Vijay Kartik, Ming Jiang

In the context of next-generation radio interferometers, we are facing a big challenge of how to economically process data. The classical dimensionality reduction technique, averaging visibilities on time, may dilute fast radio transients (FRT). We propose ...

2019

Convergence of the Exponentiated Gradient Method with Armijo Line Search

Volkan Cevher, Yen-Huan Li

Consider the problem of minimizing a convex differentiable function on the probability simplex, spectrahedron, or set of quantum density matrices. We prove that the expo-nentiated gradient method with Armijo line search always converges to the optimum, if ...

2019

Performance characterization of Altera and Xilinx 28 nm FPGAs at cryogenic temperatures

Edoardo Charbon, Harald Arjan Robert Homulle

Quantum computers enable a massive speed-up in calculations, thanks to the nature of quantum operations. To unlock quantum computation, a classical system infrastructure is required for the control of qubits and processing of their data. While qubits are g ...

2018

Polar Codes for Arbitrary Classical-Quantum Channels and Arbitrary cq-MACs

We prove polarization theorems for arbitrary classical-quantum (cq) channels. The input alphabet is endowed with an arbitrary Abelian group operation, and an Anion-style transformation is applied using this operation. It is shown that as the number of pola ...

2018

The impact of classical control electronics on qubit fidelity

Edoardo Charbon, Fabio Sebastiano

Quantum processors rely on classical electronic controllers to manipulate and read out the quantum state. As the performance of the quantum processor improves, non-idealities in the classical controller can become the performance bottleneck for the whole q ...

2018

A quantum electronic device

Bálint Náfrádi

This disclosure relates to quantum electronic devices for storing qubits. In particular, this disclosure relates to a quantum electronic device comprising a carbon nanosphere adapted to store a qubit represented by an electron spin and a control and readou ...

2017

On the -Betti numbers of universal quantum groups

Sven Raum

We show that the first -Betti number of the duals of the free unitary quantum groups is one, and that all -Betti numbers vanish for the duals of the quantum automorphism groups of full matrix algebras. ...

Springer Heidelberg2017

L-2-Betti Numbers Of Rigid C*-Tensor Categories And Discrete Quantum Groups

Sven Raum

We compute the L-2-Betti numbers of the free C*-tensor categories, which are the representation categories of the universal unitary quantum groups A(u)(F). We show that the L-2-Betti numbers of the dual of a compact quantum group G are equal to the L-2-Bet ...

Mathematical Science Publ2017