nanotune.device.device_channel

class nanotune.device.device_channel.DeviceChannel(station: Station, channel: Union[str, InstrumentChannel], gate_id: Optional[int] = None, ohmic_id: Optional[int] = None, label: str = 'device_channel', safety_voltage_range: Tuple[float, float] = (-3, 0), use_ramp: bool = True, ramp_rate: float = 0.1, max_voltage_step: float = 0.05, post_delay: float = 0.001, inter_delay: float = 0.001, **kwargs)[source]

Bases: InstrumentChannel

Class representing a channel of a device such as gate or ohmic.

It emulates an existing intrument channel and adds convenience functionality for tuning. It implements its own voltage setting method which, for example, checks whether the value is within the safety range before starting to set anything - as opposed to qcodes. The emulated channel must be a channel of a subclass of nanotune.drivers.dac_interface.DACInterface. When setting a voltage, it can be either ramped or set, specified by the use_ramp parameter. A hardware ramp is performed if the underlying instrument channel supports it, which is indicated by the supports_hardware_ramp property. Otherwise QCoDeS’ software ramp using delay and step properties is used.

Parameters

  • gate_id – Integer identifier of the gate with respect to the device layout. Not to be set if it is an ohmic.

  • ohmic_id – Integer identifier of the ohmic with respect to the device layout. Not to be set if it is a gate.

  • label – String identifier to be printed on plots.

  • safety_voltage_range – Range of voltages within which safe operation is guaranteed.

  • use_ramp – Whether voltages should be ramped.

  • ramp_rate – Rate at which voltages should be ramped. In V/s.

  • max_voltage_step – Maximum voltage difference to be applied in a single step. Note that this step does not apply when use_ramp is set to False.

  • post_delay – Delay to wait after a voltage is set, in seconds. If ramping in software (supports_hardware_ramp == False and use_ramp() == True and thus using QCoDeS’ delay and step parameter) and inter_delay is not set, then post_delay will be used.

  • inter_delay – Delay to wait between voltage setpoints, in seconds. If set to zero but post_delay is not zero, software ramp (supports_hardware_ramp == False and use_ramp() == True) will take the post_delay as delay between sets.

  • supports_hardware_ramp – Bool indicating whether under the underlying instrument channel supports voltage ramping in hardware.

  • relay_state – State of DAC relay, one of nanotune.dac_interface.RelayState’s members.

  • frequency – Frequency parameter, part of the AWG functionality of the underlying channel (if supported - as defined by the instance of DACInterface instance).

  • offset – Offset parameter, part of the AWG functionality of the underlying channel (if supported - as defined by the instance of DACInterface instance).

  • amplitude – Amplitude parameter, part of the AWG functionality of the underlying channel (if supported - as defined by the instance of DACInterface instance).

property gate_id: Optional[int]

Device layout ID of a gate.

property ohmic_id: Optional[int]

Device layout ID of an ohmic.

property supports_hardware_ramp: float

Boolean indication whether the underlying instrument channel supports hardware ramp.

property post_delay: float

Waiting time in seconds after a sequence of set operations.

property inter_delay: float

Waiting time in seconds between set operations.

property max_voltage_step: float

Maximum voltage difference between consecutive voltage sets.

ground() → None[source]

Set relay state to ground.

float_relay() → None[source]

Set relay state to float.

set_voltage(new_value: float, tol: float = 1e-05)[source]

Voltage setter.

It checks if the new value is within safety ranges before setting anything - as opposed to qcodes, which throws an error only once the safety range is reached. It ramps to the new value if ramping is enabled, using either software or hardware ramps - depending on supports_hardware_ramp. It’s a blocking ramp. :param new_value: New voltage value to set. :param tol: Tolerance in Volt. Used to check if ramp has finished.