Allow definition of a custom phase jump time + Suppress output modula…

…tion for phase (#779)

* Adding Channel.custom_phase_jump_time

* Restrict phase jump time for EOM mode

* Eliminate modulation for phase

* Unit tests

* Improve docstring

pulser-core/pulser/channels/base_channel.py

@@ -34,7 +34,11 @@
 
 ChannelType = TypeVar("ChannelType", bound="Channel")
 
-OPTIONAL_ABSTR_CH_FIELDS = ("min_avg_amp", "propagation_dir")
+OPTIONAL_ABSTR_CH_FIELDS = (
+    "min_avg_amp",
+    "custom_phase_jump_time",
+    "propagation_dir",
+)
 
 # States ranked in decreasing order of their associated eigenenergy
 States = Literal["u", "d", "r", "g", "h", "x"]
@@ -78,6 +82,9 @@ class Channel(ABC):
         min_avg_amp: The minimum average amplitude of a pulse (when not zero).
         mod_bandwidth: The modulation bandwidth at -3dB (50% reduction), in
             MHz.
+        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.
 
@@ -97,6 +104,7 @@ class Channel(ABC):
     max_duration: Optional[int] = int(1e8)  # ns
     min_avg_amp: float = 0
     mod_bandwidth: Optional[float] = None  # MHz
+    custom_phase_jump_time: int | None = None
     eom_config: Optional[BaseEOM] = field(init=False, default=None)
     propagation_dir: tuple[float, float, float] | None = None
 
@@ -172,13 +180,15 @@ def __post_init__(self) -> None:
             "max_duration",
             "mod_bandwidth",
             "min_avg_amp",
+            "custom_phase_jump_time",
         ]
         non_negative = [
             "max_amp",
             "max_abs_detuning",
             "min_retarget_interval",
             "fixed_retarget_t",
             "min_avg_amp",
+            "custom_phase_jump_time",
         ]
         local_only = [
             "min_retarget_interval",
@@ -191,6 +201,7 @@ def __post_init__(self) -> None:
             "max_duration",
             "mod_bandwidth",
             "max_targets",
+            "custom_phase_jump_time",
         ]
 
         if self.addressing == "Global":
@@ -280,9 +291,14 @@ def rise_time(self) -> int:
     def phase_jump_time(self) -> int:
         """Time taken to change the phase between consecutive pulses (in ns).
 
-        Corresponds to two times the rise time.
+        Corresponds to two times the rise time when `custom_phase_jump_time`
+        is not defined.
         """
-        return self.rise_time * 2
+        return int(
+            self.rise_time * 2
+            if self.custom_phase_jump_time is None
+            else self.custom_phase_jump_time
+        )
 
     def is_virtual(self) -> bool:
         """Whether the channel is virtual (i.e. partially defined)."""
@@ -336,6 +352,9 @@ def Local(
                 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.
         """
         # Can't initialize a channel whose addressing is determined internally
         for cls_field in fields(cls):
@@ -382,6 +401,9 @@ def Global(
                 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.
         """

pulser-core/pulser/json/abstract_repr/schemas/device-schema.json

@@ -31,6 +31,13 @@
           "description": "The duration of a clock cycle (in ns).",
           "type": "number"
         },
+        "custom_phase_jump_time": {
+          "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+          "type": [
+            "number",
+            "null"
+          ]
+        },
         "eom_config": {
           "description": "Configuration of an associated EOM.",
           "type": "null"
@@ -417,6 +424,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "anyOf": [
                 {
@@ -587,6 +601,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -693,6 +714,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -799,6 +827,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "anyOf": [
                 {
@@ -972,6 +1007,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -1081,6 +1123,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -1195,6 +1244,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "anyOf": [
                 {
@@ -1356,6 +1412,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -1453,6 +1516,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -1550,6 +1620,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "anyOf": [
                 {
@@ -1711,6 +1788,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -1808,6 +1892,13 @@
               "description": "The duration of a clock cycle (in ns).",
               "type": "number"
             },
+            "custom_phase_jump_time": {
+              "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+              "type": [
+                "number",
+                "null"
+              ]
+            },
             "eom_config": {
               "description": "Configuration of an associated EOM.",
               "type": "null"
@@ -1911,6 +2002,13 @@
           "description": "The duration of a clock cycle (in ns).",
           "type": "number"
         },
+        "custom_phase_jump_time": {
+          "description": "An optional custom value for the phase jump time that overrides the  default value estimated from the modulation bandwidth.",
+          "type": [
+            "number",
+            "null"
+          ]
+        },
         "eom_config": {
           "description": "Configuration of an associated EOM.",
           "type": "null"

pulser-core/pulser/sampler/samples.py

@@ -424,9 +424,16 @@ def masked(
             new_samples["amp"] = channel_obj.modulate(self.amp)
             new_samples["det"] = channel_obj.modulate(self.det, keep_ends=True)
 
-        new_samples["phase"] = channel_obj.modulate(self.phase, keep_ends=True)
-        new_samples["_centered_phase"] = channel_obj.modulate(
-            self.centered_phase, keep_ends=True
+        new_len_ = len(new_samples["amp"])
+        new_samples["phase"] = pm.pad(
+            self.phase,
+            (0, new_len_ - len(self.phase)),
+            mode="edge",
+        )
+        new_samples["_centered_phase"] = pm.pad(
+            self.centered_phase,
+            (0, new_len_ - len(self.centered_phase)),
+            mode="edge",
         )
         for key in new_samples:
             new_samples[key] = new_samples[key].astype(float)[

pulser-core/pulser/sequence/_schedule.py

@@ -434,11 +434,14 @@ def corrected_phase(tf: int) -> pm.AbstractArray:
                     # last pulse from the phase_jump_time and adds the
                     # fall_time to let the last pulse ramp down
                     ch_obj = self[channel].channel_obj
+                    in_eom_mode = self[channel].in_eom_mode()
                     phase_jump_buffer = (
-                        ch_obj.phase_jump_time
-                        + last_pulse.fall_time(
-                            ch_obj, in_eom_mode=self[channel].in_eom_mode()
+                        max(
+                            ch_obj.phase_jump_time,
+                            # In EOM mode, we must wait at least 2*rise_time
+                            2 * ch_obj.rise_time * in_eom_mode,
                         )
+                        + last_pulse.fall_time(ch_obj, in_eom_mode=in_eom_mode)
                         - (t0 - last_pulse_slot.tf)
                     )
             except RuntimeError:

tests/test_abstract_repr.py

@@ -513,6 +513,7 @@ def test_optional_device_fields(self, og_device, field, value):
         [
             Rydberg.Global(None, None, min_avg_amp=1),
             Rydberg.Global(None, None, propagation_dir=(1, 0, 0)),
+            Rydberg.Global(None, None, custom_phase_jump_time=0),
             Rydberg.Global(
                 None,
                 None,

tests/test_channels.py

@@ -38,6 +38,7 @@
         ("min_avg_amp", -1e-3),
         ("propagation_dir", (0, 0, 0)),
         ("propagation_dir", [1, 0]),
+        ("custom_phase_jump_time", -10),
     ],
 )
 def test_bad_init_global_channel(bad_param, bad_value):
@@ -66,6 +67,7 @@ def test_bad_init_global_channel(bad_param, bad_value):
         ("mod_bandwidth", MODBW_TO_TR * 1e3 + 1),
         ("min_avg_amp", -1e-3),
         ("propagation_dir", (1, 0, 0)),
+        ("custom_phase_jump_time", -0.5),
     ],
 )
 def test_bad_init_local_channel(bad_param, bad_value):