Zobrazeno 1 - 10
of 329
pro vyhledávání: '"Navascués, Miguel"'
Non-commutative polynomial optimization (NPO) problems seek to minimize the state average of a polynomial of some operator variables, subject to polynomial constraints, over all states and operators, as well as the Hilbert spaces where those might be
Externí odkaz:
http://arxiv.org/abs/2408.02572
We study what can or cannot be certified in communication scenarios where the assumption of independence and identical distribution (iid) between experimental rounds fails. In this respect, we prove that membership tests for non-convex sets of correl
Externí odkaz:
http://arxiv.org/abs/2402.12318
We consider the problem of optimizing the state average of a polynomial of non-commuting variables, over all states and operators satisfying a number of polynomial constraints, and over all Hilbert spaces where such states and operators are defined.
Externí odkaz:
http://arxiv.org/abs/2311.18707
Publikováno v:
Phys. Rev. Lett. 131, 250802 (2023)
We consider communication scenarios where one party sends quantum states of known dimensionality $D$, prepared with an untrusted apparatus, to another, distant party, who probes them with uncharacterized measurement devices. We prove that, for any en
Externí odkaz:
http://arxiv.org/abs/2306.00730
Publikováno v:
PRX Quantum 5, 020351 (2024)
Many problems in quantum information theory can be formulated as optimizations over the sequential outcomes of dynamical systems subject to unpredictable external influences. Such problems include many-body entanglement detection through adaptive mea
Externí odkaz:
http://arxiv.org/abs/2302.02918
Publikováno v:
Phys. Rev. X 14, 021008 (9 April 2024)
Given a renormalization scheme, we show how to formulate a tractable convex relaxation of the set of feasible local density matrices of a many-body quantum system. The relaxation is obtained by introducing a hierarchy of constraints between the reduc
Externí odkaz:
http://arxiv.org/abs/2212.03014
Publikováno v:
Quantum 7, 1019 (2023)
Computing the key rate in quantum key distribution (QKD) protocols is a long standing challenge. Analytical methods are limited to a handful of protocols with highly symmetric measurement bases. Numerical methods can handle arbitrary measurement base
Externí odkaz:
http://arxiv.org/abs/2211.05725
Publikováno v:
npj Quantum Inf 9, 69 (2023)
Consider a scenario where a quantum particle is initially prepared in some bounded region of space and left to propagate freely. After some time, we verify if the particle has reached some distant target region. We find that there exist "ultrafast" (
Externí odkaz:
http://arxiv.org/abs/2209.00725
We present a universal mechanism that, acting on any target qubit, propagates it to the state it had T time units before the experiment started. This protocol works by setting the target on a superposition of flight paths, where it is acted on by unc
Externí odkaz:
http://arxiv.org/abs/2205.01131
Autor:
Schiansky, Peter, Strömberg, Teodor, Trillo, David, Saggio, Valeria, Dive, Ben, Navascués, Miguel, Walther, Philip
Publikováno v:
Optica Vol. 10, Issue 2, pp. 200-205 (2023)
Although the laws of classical physics are deterministic, thermodynamics gives rise to an arrow of time through irreversible processes. In quantum mechanics the unitary nature of the time evolution makes it intrinsically reversible, however the quest
Externí odkaz:
http://arxiv.org/abs/2205.01122