Raman

class pulser.channels.Raman(addressing, max_abs_detuning, max_amp, min_retarget_interval=None, fixed_retarget_t=None, max_targets=None, clock_period=1, min_duration=1, max_duration=100000000, min_avg_amp=0, mod_bandwidth=None, custom_phase_jump_time=None, propagation_dir=None)

Bases: Channel

Raman beam channel.

Channel targeting the transition between the hyperfine ground states, in which the ‘digital’ basis is encoded. See base class.

Attributes

basis	The addressed basis name.
clock_period
custom_phase_jump_time
eigenstates	The eigenstates associated with the basis.
eom_config
fixed_retarget_t
max_duration
max_targets
min_avg_amp
min_duration
min_retarget_interval
mod_bandwidth
name	The name of the channel.
phase_jump_time	Time taken to change the phase between consecutive pulses (in ns).
propagation_dir
rise_time	The rise time (in ns).
addressing
max_abs_detuning
max_amp

Methods

Global	Initializes the channel with global addressing.
Local	Initializes the channel with local addressing.
apply_modulation	Applies the modulation transfer fuction to the input samples.
calc_modulation_buffer	Calculates the minimal buffers needed around a modulated waveform.
default_id	Generates the default ID for indexing this channel in a Device.
is_virtual	Whether the channel is virtual (i.e. partially defined).
modulate	Modulates the input according to the channel's modulation bandwidth.
supports_eom	Whether the channel supports EOM mode operation.
validate_duration	Validates and adapts the duration of an instruction on this channel.
validate_pulse	Checks if a pulse can be executed this channel.

Signatures

classmethod Global(max_abs_detuning, max_amp, **kwargs)

Initializes the channel with global addressing.

Parameters:

• max_abs_detuning (float | None) – Maximum possible detuning (in rad/µs), in absolute value.

• max_amp (float | None) – Maximum pulse amplitude (in rad/µs).

Keyword Arguments:

• clock_period (int, default=4) – The duration of a clock cycle (in ns). The duration of a pulse or delay instruction is enforced to be a multiple of the clock cycle.

• min_duration (int, default=1) – The shortest duration an instruction can take.

• max_duration (Optional[int], default=10000000) – The longest duration an instruction can take.

• mod_bandwidth (Optional[float], default=None) – The modulation bandwidth at -3dB (50% reduction), in MHz.

• min_avg_amp – The minimum average amplitude of a pulse (when not zero).

• custom_phase_jump_time – An optional custom value for the phase jump time that overrides the default value estimated from the modulation bandwidth. It is not enforced in EOM mode.

• propagation_dir – The propagation direction of the beam associated with the channel, given as a vector in 3D space.

Return type:

TypeVar(ChannelType, bound= Channel)

classmethod Local(max_abs_detuning, max_amp, min_retarget_interval=0, fixed_retarget_t=0, max_targets=None, **kwargs)

Initializes the channel with local addressing.

Parameters:

• max_abs_detuning (float | None) – Maximum possible detuning (in rad/µs), in absolute value.

• max_amp (float | None) – Maximum pulse amplitude (in rad/µs).

• min_retarget_interval (int, default: 0) – Minimum time required between two target instructions (in ns).

• fixed_retarget_t (int, default: 0) – Time taken to change the target (in ns).

• max_targets (int | None, default: None) – Maximum number of atoms the channel can target simultaneously.

Keyword Arguments:

• clock_period (int, default=4) – The duration of a clock cycle (in ns). The duration of a pulse or delay instruction is enforced to be a multiple of the clock cycle.

• min_duration (int, default=1) – The shortest duration an instruction can take.

• max_duration (Optional[int], default=10000000) – The longest duration an instruction can take.

• mod_bandwidth (Optional[float], default=None) – The modulation bandwidth at -3dB (50% reduction), in MHz.

• min_avg_amp – The minimum average amplitude of a pulse (when not zero).

• custom_phase_jump_time – An optional custom value for the phase jump time that overrides the default value estimated from the modulation bandwidth. It is not enforced in EOM mode.

Return type:

TypeVar(ChannelType, bound= Channel)

static apply_modulation(input_samples, mod_bandwidth)

Applies the modulation transfer fuction to the input samples.

Note

This is strictly the application of the modulation transfer function. The samples should be padded beforehand.

Parameters:

• input_samples (ArrayLike) – The samples to modulate.

• mod_bandwidth (float) – The modulation bandwidth at -3dB (50% reduction), in MHz.

Return type:

AbstractArray

calc_modulation_buffer(input_samples, mod_samples, max_allowed_diff=0.01, eom=False)

Calculates the minimal buffers needed around a modulated waveform.

Parameters:

• input_samples (ArrayLike) – The input samples.

• mod_samples (ArrayLike) – The modulated samples. Must be of size len(input_samples) + 2 * self.rise_time.

• max_allowed_diff (float, default: 0.01) – The maximum allowed difference between the input and modulated samples at the end points.

• eom (bool, default: False) – Whether to calculate the modulation buffers with the EOM bandwidth.

Return type:

tuple[int, int]

Returns:

The minimum buffer times at the start and end of the samples, in ns.

default_id()

Generates the default ID for indexing this channel in a Device.

Return type:

str

is_virtual()

Whether the channel is virtual (i.e. partially defined).

Return type:

bool

modulate(input_samples, keep_ends=False, eom=False)

Modulates the input according to the channel’s modulation bandwidth.

Parameters:

• input_samples (ArrayLike) – The samples to modulate.

• keep_ends (bool, default: False) – Assume the end values of the samples were kept constant (i.e. there is no ramp from zero on the ends).

• eom (bool, default: False) – Whether to calculate the modulation using the EOM bandwidth.

Return type:

AbstractArray

Returns:

The modulated output signal.

supports_eom()

Whether the channel supports EOM mode operation.

Return type:

bool

validate_duration(duration)

Validates and adapts the duration of an instruction on this channel.

Parameters:

duration (int) – The duration to validate.

Return type:

int

Returns:

The duration, potentially adapted to the channels specs.

validate_pulse(pulse)

Checks if a pulse can be executed this channel.

Parameters:

pulse (Pulse) – The pulse to validate.

Return type:

None

property basis: Literal['digital']

The addressed basis name.

property eigenstates: list[Literal['u', 'd', 'r', 'g', 'h', 'x']]

The eigenstates associated with the basis.

Returns a tuple of labels, ranked in decreasing order of their associated eigenenergy, as such:

Name	Eigenstate (see Conventions)	Associated label
Up state	\(|0\rangle\)	"u"
Down state	\(|1\rangle\)	"d"
Rydberg state	\(|r\rangle\)	"r"
Ground state	\(|g\rangle\)	"g"
Hyperfine state	\(|h\rangle\)	"h"
Error state	\(|x\rangle\)	"x"

property name: str

The name of the channel.

property phase_jump_time: int

Time taken to change the phase between consecutive pulses (in ns).

Corresponds to two times the rise time when custom_phase_jump_time is not defined.

property rise_time: int

The rise time (in ns).

Defined as the time taken to go from 10% to 90% output in response to a step change in the input.