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 …

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 …

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 …

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 …

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 …

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 …

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 …

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. XXXXX, we have established the method of
characterizing the maximal order of approximate unitary designs generated by symmetric …

Embedded Complexity and Quantum Circuit Volume

Z Du, ZW Liu, X Ma - arXiv preprint arXiv:2408.16602, 2024 - arxiv.org
Quantum circuit complexity is a pivotal concept in quantum information, quantum many-body
physics, and high-energy physics. While extensively studied for closed systems, the …

Anti-Concentration for the Unitary Haar Measure and Applications to Random Quantum Circuits

B Fefferman, S Ghosh, W Zhan - arXiv preprint arXiv:2407.19561, 2024 - arxiv.org
We prove a Carbery-Wright style anti-concentration inequality for the unitary Haar measure,
by showing that the probability of a polynomial in the entries of a random unitary falling into …