# Application notes

**See how we have applied Boulder Opal to solve major challenges in the field.**

## Superconducting quantum computing

- Designing noise-robust single-qubit gates for IBM Qiskit
- Increasing robustness against dephasing and control noise using Q-CTRL pulses
- Performing model-based robust optimization for the cross-resonance gate
- Increasing robustness against crosstalk in a two-qubit entangling operation
- Demonstrating SU(3) gates on superconducting hardware
- Hamiltonian-agnostic rapid tune-up of an arbitrary unitary on a qutrit
- Designing fast optimal SNAP gates in superconducting resonators
- Engineering fast, leakage-free gates in superconducting cavity-qubit systems
- Performing optimal Fock state generation in superconducting resonators
- Engineering fast cavity state generation in superconducting cavity-qubit systems
- Improving readout performance in superconducting qubits using machine learning
- Using Q-CTRL discriminators and optimized measurement parameters to boost readout performance
- Designing error-robust digital SFQ controls for superconducting qubits
- Generating single flux quantum gates robust to leakage and frequency drift

## Atomic quantum computing

- Designing robust, configurable, parallel gates for large trapped-ion arrays
- Obtaining control solutions for parallel and specifiable multi-qubit gates using Q-CTRL pulses
- Designing robust Mølmer–Sørensen gates with parametric trap drive amplification
- Obtaining control solutions for two-qubit gates with modulation of the confining potential
- Generating highly-entangled states in large Rydberg-atom arrays
- Generating high-fidelity GHZ states using Q-CTRL pulses

## Quantum sensing

- Performing narrow-band magnetic-field spectroscopy with NV centers
- Using Boulder Opal spectrum reconstruction tools to perform provably optimal leakage-free sensing with spectrally concentrated Slepian pulses
- Boosting signal-to-noise by 10X in cold-atom sensors using robust control
- Using Q-CTRL robust Raman pulses to boost fringe contrast in tight-SWAP cold atom interferometers by an order of magnitude