Expression

An expression is a mathematical formula that can be evaluated.

Expressions can either be evaluated once at the beginning of a sequence, or multiple times for each shot.

When an expression is evaluated for each shot, its value can be different every time if it depends on a variable that changes between shots.

Analog expression

An analog expression is a mathematical expression that takes either a real value or a dimensioned value.

  • 10: a constant value

  • 40 kHz: a constant value with a unit

  • (10 MHz + 20 kHz) / 2: an algebraic formula

  • sin(0.5): a formula with a function

  • 5 * red_mot.detuning: a formula with a variable

Digital expression

A digital expression is a mathematical expression that takes only two values: Enabled or Disabled.

It can be one of the following:

  • A digital constant, such as Enabled or Disabled.

  • The name of a parameter that has a digital value.

  • A function that returns a digital value.

Available functions

square_wave(x, duty=0.5)

Return a periodic square waveform.

Arguments

  • x: The variable over which to evaluate the waveform.

    When the fractional part of x is between 0 and duty, the waveform is Enabled. When the fractional part of x is between duty and 1, the waveform is Disabled.

    Must be a dimensionless analog expression. Can be either a scalar or a time-dependent expression.

  • duty: The duty cycle of the square wave, optional.

    Must be an expression that evaluates to a dimensionless scalar in the interval [0,1].

Example

square_wave(t * 1 kHz - 0.2, 60%) returns a square wave with a frequency of 1 kHz, an initial phase of 0.2, and a duty cycle of 60%.

Warning

  • For instruments that don’t support loop instructions, the square_wave function will be unrolled. This can result in a long programming time on the instrument.

  • The period of the square wave is rounded to the nearest integer multiple of the instrument’s time step.

Added in version 6.18.0.