This Parquet dataset packages the OpenQASM circuits used to evaluate Operator Loschmidt Echo (OLE) protocols for observable estimation, operator hydrodynamics, and OTOC-style diagnostics. The circuits originate from the Quantum Advantage Tracker’s classically verifiable observable estimation problems and are described in Algorithmiq’s 2025 report “Loschmidt echo for probing operator hydrodynamics in heterogeneous structures.” By preserving raw QASM and structured metadata in a columnar format, the dataset supports scalable analytics, ML workflows, and benchmarking across classical simulators and NISQ-era hardware.
Scientific Background
The Operator Loschmidt Echo is defined as fδ(O)=2n1Tr(UOU†Vδ†UOU†Vδ), where O∈I,Z⊗n satisfies Tr(O2)=1, U is a unitary generated by Trotterized Ising-like dynamics, and Vδ=e−iδG is a local perturbation with generator G=∑u∈PXu. The encoded unitary follows U=(U−b†)LUbL, so 2L is the number of Trotter steps, and site-dependent fields ( bu ) split the lattice into disjoint subsets ( F ) and ( S ) (e.g., heavy-hex vs. square sites). In the small-δ) regime, the OLE reduces to an out-of-time-ordered-correlator-like expression that probes operator spreading and hydrodynamics. The circuits implement random computational-basis sampling of $ f_\delta^z(O) $, and the estimator variance scales as O(1/Ninit). All circuits were produced by Algorithmiq, IBM, and the Flatiron Institute as part of the observable estimations tracker.
operator_loschmidt_echo_49x1296: 49 qubits, L=6, δ=0.15, same observable O=Z52Z59Z72.
operator_loschmidt_echo_70x1872: 70 qubits, L=6, δ=0.15, observable O=Z52Z59Z72.
Each circuit mirrors the protocol U2†U1 with a perturbation Vδ inserted between scrambling and unscrambling phases, yielding an operator-sensitive echo readout.
Dataset Contents
Every Parquet row corresponds to one complete OLE circuit instance stored as verbatim OpenQASM. Metadata such as qubit count, Floquet depth L, perturbation strength δ, gate counts, and observable structure are parsed from filenames and circuit text whenever the information is encoded. No recompilation, transpilation, or scientific modification has been applied; the conversion solely repackages .qasm sources into a columnar layout.
Schema
Column
Type
Description
circuit_id
String
Filename stem uniquely identifying the OLE instance.
family
String
Constant label operator_loschmidt_echo.
num_qubits
Int32
Number of qubits declared in the circuit.
num_gates
Int32
Total instruction count (excludes qreg/creg/gate definitions).
num_two_qubit_gates
Int32
Count of instructions acting on exactly two distinct qubits.
