Random unitaries in extremely low depth

T Schuster, J Haferkamp, HY Huang - arxiv preprint arxiv:2407.07754, 2024 - arxiv.org
We prove that random quantum circuits on any geometry, including a 1D line, can form
approximate unitary designs over $ n $ qubits in $\log n $ depth. In a similar manner, we …

Classically estimating observables of noiseless quantum circuits

A Angrisani, A Schmidhuber, MS Rudolph… - arxiv preprint arxiv …, 2024 - arxiv.org
We present a classical algorithm for estimating expectation values of arbitrary observables
on most quantum circuits across all circuit architectures and depths, including those with all …

Efficient quantum pseudorandomness from hamiltonian phase states

J Bostanci, J Haferkamp, D Hangleiter… - arxiv preprint arxiv …, 2024 - arxiv.org
Quantum pseudorandomness has found applications in many areas of quantum information,
ranging from entanglement theory, to models of scrambling phenomena in chaotic quantum …

[PDF][PDF] Approximate -Designs in Generic Circuit Architectures

D Belkin, J Allen, S Ghosh, C Kang, S Lin, J Sud… - PRX Quantum, 2024 - APS
Unitary t-designs are distributions on the unitary group whose first t moments appear
maximally random. Previous work has established several upper bounds on the depths at …

Characterization of randomness in quantum circuits of continuous gate sets

Y Mitsuhashi, R Suzuki, T Soejima… - arxiv preprint arxiv …, 2024 - arxiv.org
In the accompanying paper of arxiv: 2408.13472, we have established the method of
characterizing the maximal order of approximate unitary designs generated by symmetric …

Random ensembles of symplectic and unitary states are indistinguishable

M West, AA Mele, M Larocca, M Cerezo - arxiv preprint arxiv:2409.16500, 2024 - arxiv.org
A unitary state $ t $-design is an ensemble of pure quantum states whose moments match
up to the $ t $-th order those of states uniformly sampled from a $ d $-dimensional Hilbert …

Exact spectral gaps of random one-dimensional quantum circuits

AE Deneris, P Bermejo, P Braccia, L Cincio… - arxiv preprint arxiv …, 2024 - arxiv.org
The spectral gap of local random quantum circuits is a fundamental property that determines
how close the moments of the circuit's unitaries match those of a Haar random distribution …

Approximate Unitary -Designs from Shallow, Low-Communication Circuits

N LaRacuente, F Leditzky - arxiv preprint arxiv:2407.07876, 2024 - arxiv.org
Random unitaries are useful in quantum information and related fields but hard to generate
with limited resources. An approximate unitary $ k $-design is an ensemble of unitaries and …

Quantum and classical dynamics with random permutation circuits

B Bertini, K Klobas, P Kos, D Malz - arxiv preprint arxiv:2407.11960, 2024 - arxiv.org
Understanding thermalisation in quantum many-body systems is among the most enduring
problems in modern physics. A particularly interesting question concerns the role played by …

Permutation gates in the third level of the Clifford hierarchy

Z He, L Robitaille, X Tan - arxiv preprint arxiv:2410.11818, 2024 - arxiv.org
The Clifford hierarchy is a fundamental structure in quantum computation, classifying unitary
operators based on their commutation relations with the Pauli group. Despite its …