# 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 Boulder Opal pulses

### Designing noise-robust single-qubit gates for Rigetti Quil-T

Increasing robustness against control noise using Boulder Opal 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

### Designing error-robust digital SFQ controls for superconducting qubits

Generating single flux quantum gates robust to leakage and frequency drift

### Performing noise spectroscopy in superconducting hardware

Reconstructing noise power spectrum density in transmon qubits using dynamical decoupling sequences

## Atomic quantum computing

### Designing robust, configurable, parallel gates for large trapped-ion arrays

Obtaining control solutions for parallel and specifiable multi-qubit gates using Boulder Opal 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 Boulder Opal pulses

### Designing robust Rydberg blockade two-qubit gates in cold atoms

Using Boulder Opal to improve two-qubit controlled-Z gates for cold atoms

## Quantum sensing

### Designing robust pulses for widefield microscopy with NV centers

Increasing detection area by $>10\times$ using $\pi$ pulses robust to field inhomogeneities across large diamond chips

### 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 Boulder Opal robust Raman pulses to boost fringe contrast in tight-SWAP cold atom interferometers by an order of magnitude