QIDE JSON Circuit Definition

A QIDE JSON document defines a quantum computing circuit - any circuit diagram can be represented in QIDE JSON. The document consists of a top level set of properties that describe the quantum circuit (i.e. the qubit count) along with an array of gate objects. Here's a simple example of a Bell state circuit with two qubits:

{
  "qubit_count": 2,
  "gates": [
    {
      "gate_type": "H",
      "target_qubits": [ 0 ]
    },
    {
      "gate_type": "CNOT",
      "control_qubits": [ 0 ],
      "target_qubits": [ 1 ]
    },
    {
      "gate_type": "M",
      "target_qubits": [ 0, 1 ]
    }
  ]
}

Top Level Properties

qubit_count: (Number) The number of qubits in the circuit.
ignore_danger: (Boolean) If the qubit_count is greater than the warning default (currently 16), then this flag must be set to true in order for the circuit to be run. State vectors grow exponentially based on the qubit_count therefore it is easy to use up all memory simply by setting the number of qubits too large.
gates: (Array) The list of Gates in the circuit.
use_2_bit: (Boolean) Only used for Bloch diagrams as it provides qubit state values prior to being entangled.

parameters: (Object) User defined properties that can be used in rvalue expressions (the rvalue_expr property of a gate object). For example:

{
  "qubit_count": 2,
  "parameters": {
        "param1": 1.14159
  },
  "gates": [
      {
          "gate_type": "R1",
          "target_qubits": [
              1
          ],
          "rvalue_expr": "1.0 * param1 / 2.0",
      }
  ]
}

Gate Object Properties

The following properties define the basics of a gate - the type and any control or target qubits.

gate_type: (String) One of any of the documented gate types such as standard gates.
target_qubits: (Array) List of qubits to which the gate is applied.
control_qubits: (Array) List of qubits that act as the controlling qubits. Note that only a single qubit can be specified as a target_qubit when control qubits are specified.

R-value Options

The following properties are used in gates that require and r-value.

rvalue: (Number) A radian value used in R r-value gates. For example:

{
    "gate_type": "R1",
    "target_qubits": [ 1 ],
    "rvalue": 3.14
}

rvalue_dyadic_denom: (Number) Used in conjunction with rvalue, this sets the r-value to the computation (rvalue * pi / 2 ^ rvalue_dyadic_denom)
rvalue_expr: (String) A mathematical expression that defines the r-value and can use parameters or built-in constants such as pi. These expressions are implemented using the meval Rust crate and its documentation can be referred to for more information.
```
{
    "gate_type": "Rx",
    "target_qubits": [ 1 ],
    "rvalue_expr": "pi / 2.0",
}
```

Advanced Properties

adjoint: (Boolean) If true then the adjoint (conjugated transpose) of the gate matrix is applied. This is used in "undo-ing" prior gates used to potentially measure a qubit in a different basis, and are set automatically in conjugate composite gates.
rand_source_type: (String) Used in measurement gates to determine the source of the random numbers used to collapse a qubit's state. If set to RandRng, a software random number generator is used. If set to RandomSeed the RDS Random Seed service is used.
within_gates, apply_gates: (Array) Both arrays contain a list of gate objects and are used in composite gates.

Informational Properties

The following gates are used to document a circuit within the json document. They are not used in any calculations and may be set to whatever the designer wishes.

gate_name: (String) Can be used to name a gate.
comment: (String) Can be used to describe or document a gate or block.