Quantum-state manipulation and detection

Optical pumping and state-dependent fluorescence detection of ionic quantum states, using Quatm’s precise timing and statistical analysis.

Overview

This experiment script provides the class state_prep: it optically pumps the ion into the S1/2 or D3/2 state and can optionally apply one more cooling cycle at the end. State-dependent detection then distinguishes the bright/dark states by fluorescence counting.

Parameters

on_s_off_d (pump to S1/2 (650 off) or to D3/2 (493 off)), cooling_end (whether to add one cooling step before the end).

State-preparation logic

  • S1/2: switch off the 650 light first → the ion falls into S1/2;
  • D3/2: switch off the 493 light first → the ion is pumped into D3/2.

The same logic also appears in Ion_to_S_state / Ion_to_D_state of secondinteraction, where count_ions fluorescence counting performs the state-dependent detection (bright = S1/2, dark = D3/2, etc.).

Key code (excerpt)

from quatm.experiment import Experiment, BoolValue

class state_prep(Experiment):
    def build(self):
        self.setattr_argument("on_s_off_d", BoolValue(value=False))
        self.setattr_argument("cooling_end", BoolValue(value=True))
        # ... remainder omitted

optical_dark_pumping.py (dark pumping, pumping_time_us), d_shelving.py (D-state related measurements).