Writing quantum programs.
WHAT THE MODEL IS
Circuits: sequences of operations applied to qubits, followed by measurement.
WHAT AN OPERATION IS
A gate, transforming the state of one or more qubits.
WHAT THE COMMON GATES DO
Create superposition Flip states Apply conditional operations between qubits Rotate states by an angle
WHAT FRAMEWORKS EXIST
Several, provided by hardware vendors and independent projects, generally in Python.
WHAT THEY PROVIDE
Circuit construction Simulation on classical hardware Submission to real machines Compilation to a specific machine's capabilities
WHY SIMULATION MATTERS
Real machine time is scarce and expensive, and small circuits simulate adequately.
WHAT LIMITS SIMULATION
Resource requirements growing exponentially with qubit count.
WHAT A HYBRID ALGORITHM IS
A classical loop calling a quantum routine repeatedly, adjusting parameters.
WHY THOSE DOMINATE CURRENT PRACTICE
They tolerate noise better than purely quantum algorithms.
WHAT TO LEARN FIRST
Linear algebra, probability, and the circuit model.
WHAT NOT TO EXPECT
That existing programming intuitions transfer.
