9 papers
The limits of magic-state distillation
Llorenç Balada Gaggioli, Jakub Mareček
Magic-state factories are a major cost of fault-tolerant quantum computing, yet how few noisy inputs they need is known only for restricted protocols. We show that, for tolerating…
Time-optimal robust quantum control for partially known errors
Llorenç Balada Gaggioli
Robust quantum control usually assumes one of two extremes: the error is of a known form and only its strength is unknown, or nothing at all is known about it. In practice one ofte…
Reachability and optimal-time certificates for quantum control
Younes Naceur, Llorenç Balada Gaggioli
Finite-time control is central to quantum technologies, yet rigorous limits on reachable targets and optimal control times remain largely unknown. We develop a framework for finite…
Composition and tensor train structure in polynomial optimization
Llorenç Balada Gaggioli, Didier Henrion, Milan Korda
We study polynomial optimization problems whose objective has a composition or tensor train structure. These polynomials can be evaluated as a sequence of maps, giving rise to inte…
Low-rank geometry of two-qubit gates
Llorenç Balada Gaggioli
We present a framework based on the determinantal geometry of two-qubit gates. Combining the Weyl chamber representation with operator Schmidt theory, we interpret gate synthesis a…
Global optimization of low-rank polynomials
Llorenç Balada Gaggioli, Didier Henrion, Milan Korda
This work considers polynomial optimization problems where the objective admits a low-rank canonical polyadic tensor decomposition. We introduce LRPOP (low-rank polynomial optimiza…
Time evolution of controlled many-body quantum systems with matrix product operators
Llorenç Balada Gaggioli, Jakub Mareček
We present a method for describing the time evolution of many-body controlled quantum systems using matrix product operators (MPOs). Existing techniques for solving the time-depend…
Unitary Gate Synthesis via Polynomial Optimization
Llorenç Balada Gaggioli, Denys I. Bondar, Jiri Vala +2
Quantum optimal control plays a crucial role in the development of quantum technologies, particularly in the design and implementation of fast and accurate gates for quantum comput…
Geometric quantum control and the random Schrödinger equation
Rufus Lawrence, Aleš Wodecki, Johannes Aspman +2
Understanding and mitigating noise in quantum systems is a fundamental challenge in achieving scalable and fault-tolerant quantum computation. Error modeling for quantum systems ca…