116 citations · 190 across the 12 of their papers we have counts for
13 papers · 1 filter
Unconditional quantum advantage with noisy planar architectures
Libor Caha, Robert Koenig, Louis Paletta
We consider quantum devices restricted to local operations in 2D and subject to local stochastic noise below a constant threshold. We show that such circuits are computationally mo…
Haah's 3D cubic code thermalizes rapidly
Sebastian Stengele, Libor Caha, Ángela Capel +1
Haah's 3D cubic code was introduced as a candidate for a self-correcting quantum memory in three dimensions, using the absence of string logical operators to obstruct thermal error…
Layer codes as partially self-correcting quantum memories
Shouzhen Gu, Libor Caha, Shin Ho Choe +3
We investigate layer codes, a family of three-dimensional stabilizer codes that can achieve optimal scaling of code parameters and a polynomial energy barrier, as candidates for se…
Factoring an integer with three oscillators and a qubit
Lukas Brenner, Libor Caha, Xavier Coiteux-Roy +1
A common starting point of traditional quantum algorithm design is the notion of a universal quantum computer with a scalable number of qubits. This convenient abstraction mirrors…
The complexity of Gottesman-Kitaev-Preskill states
Lukas Brenner, Libor Caha, Xavier Coiteux-Roy +1
We initiate the study of state complexity for continuous-variable quantum systems. Concretely, we consider a setup with bosonic modes and auxiliary qubits, where available operatio…
A colossal advantage: 3D-local noisy shallow quantum circuits defeat unbounded fan-in classical circuits
Libor Caha, Xavier Coiteux-Roy, Robert Koenig
We present a computational problem with the following properties: (i) Every instance can be solved with near-certainty by a constant-depth quantum circuit using only nearest-neighb…
Single-shot decoding of good quantum LDPC codes
Shouzhen Gu, Eugene Tang, Libor Caha +3
Quantum Tanner codes constitute a family of quantum low-density parity-check (LDPC) codes with good parameters, i.e., constant encoding rate and relative distance. In this article,…
Single-qubit gate teleportation provides a quantum advantage
Libor Caha, Xavier Coiteux-Roy, Robert Koenig
Gate-teleportation circuits are arguably among the most basic examples of computations believed to provide a quantum computational advantage: In seminal work [Quantum Inf. Comput.,…
Twisted hybrid algorithms for combinatorial optimization
Libor Caha, Alexander Kliesch, Robert Koenig
Proposed hybrid algorithms encode a combinatorial cost function into a problem Hamiltonian and optimize its energy by varying over a set of states with low circuit complexity. Clas…
The pair-flip model: a very entangled translationally invariant spin chain
Libor Caha, Daniel Nagaj
Investigating translationally invariant qudit spin chains with a low local dimension, we ask what is the best possible tradeoff between the scaling of the entanglement entropy of a…
Shorter unentangled proofs for Ground State Connectivity
Libor Caha, Daniel Nagaj, Martin Schwarz
Can one considerably shorten a proof for a quantum problem by using a protocol with a constant number of unentangled provers? We consider a frustration-free variant of the QCMA-com…
The Feynman-Kitaev computer's clock: bias, gaps, idling and pulse tuning
Libor Caha, Zeph Landau, Daniel Nagaj
We present a collection of results about the clock in Feynman's computer construction and Kitaev's Local Hamiltonian problem. First, by analyzing the spectra of quantum walks on a…
Criticality without frustration for quantum spin-1 chains
Sergey Bravyi, Libor Caha, Ramis Movassagh +2
Frustration-free (FF) spin chains have a property that their ground state minimizes all individual terms in the chain Hamiltonian. We ask how entangled the ground state of a FF qua…