Fresnel / Fresnel 2
Fresnel / Fresnel 2
Register profile — the machine's variant of its architecture
qubit type: ground-Rydberg analog qubit (analog mode); hyperfine (digital mode)
gate mechanism: analog Rydberg Hamiltonian evolution, with a digital mode added later
connectivity: reconfigurable tweezer register
control: SLM/AOD laser control; PIC-generated tweezers are a Pasqal research line
control placement: optics (room temperature)
readout: fluorescence imaging
gate evidence: no published figure
flags: no published error rates, source not confirmed
Technologies by layer — the machine's cell per layer
| 1 Qubit carrier | Alkali atom (Rb/Cs) in optical tweezers · primary ▣ Fig. 3a-b (main hardware components; photograph of the heart of the neutral-atom co-processor); §2 Neutral atoms arrays ✅ 100 physical 87Rb atoms; ground-Rydberg analog qubit (analog mode), hyperfine (digital mode) |
| 2 Encoding | Ground–Rydberg analogue qubit · primary ▣ Fig. 6b (analog processing: whole register illuminated, evolution under tailored Hamiltonian H); §2.2.2 Analog quantum processing 🔎 ground-Rydberg analog qubit (analog mode) Hyperfine / clock-state qubit · alternate ▣ Fig. 7 (single- and two-qubit gates on |0>,|1>); §2.2.1 Digital quantum processing 🔎 hyperfine qubit in the digital mode added later |
| 3 Gate mechanism | Analogue Rydberg Hamiltonian evolution · primary ▣ Fig. 6b (analog processing under a global laser beam); Fig. 6a-b (digital vs analog processing); §2.2.2 Analog quantum processing ✅ analog Rydberg Hamiltonian evolution (primary mode) Rydberg-blockade CZ · alternate ▣ Fig. 7b (target qubit rotates by π conditioned on control qubit); Fig. 9a (5-pulse CCZ sequence); §2.2.1 Digital quantum processing ✅ Rydberg gates in the digital mode added later |
| 4 Connectivity / transport | Atom transport by AOD tweezers (zoned architecture) · primary ▣ Fig. 3a (SLM microtraps + 2D AOD moving tweezers); Fig. 5a-b (moving an atom between sites <1 ms; rearrangement into a defect-free sub-register); Fig. 4 (2D/3D tweezer arrays); §2.1.1 Register loading ✅ reconfigurable tweezer register; 506-atom defect-free register demonstrated (2024) |
| 5 Control | Laser + AOD/SLM optical control (atoms) · primary ▣ Fig. 3a (trapping laser shaped by SLM; moving tweezers via 2D AOD and PBS); Fig. 2 (register actuators and processing actuators) ✅ SLM/AOD laser control; optics (room temperature) PIC-generated tweezers / integrated optics for atoms · alternate ▨ 🔎 PIC-generated tweezers are a Pasqal research line: 4 atoms at 27.5 s lifetimes |
| 6 Readout | Fluorescence imaging of atom arrays · primary ▣ Fig. 3a (fluorescence split by dichroic mirror and collected onto a camera); Fig. 2 (information extracted through detection of an image); §2.1.2 Register readout ✅ fluorescence imaging |
| 7 Code | — none — nothing in this layer ▤ §2.2.3 Prospects for improving the QPUs performances; Fig. 10 (three axes of hardware development) ✅ no QEC code run; analog/NISQ device |
| 8 Decoder | — none — nothing in this layer ▤ §2.2.3 Prospects for improving the QPUs performances (no decoder section) ✅ no decoder; no QEC run |
| 9 Interconnect | — none — nothing in this layer ▣ Fig. 3b (photograph of the heart of the co-processor: single vacuum setup); Fig. 3a ✅ single vacuum cell; monolithic, no interconnect |
| 10 Manufacturing | Optical / mechanical assembly (lasers, vacuum, objectives) · primary ▣ Fig. 3a-b (SLM, AOD, lens, PBS, dichroic mirror, camera around the vacuum chamber; photograph); §2.1 Operating an atomic qubit register ✅ room-temperature optical/vacuum assembly: SLM/AOD lasers around a single vacuum cell |
evidence: ✅ 10 / 13