Zhuangzi 2.0 (Chuang-tzu 2.0)

Raveh Neeman

doi:10.5281/zenodo.22674814

CAS / Peking University · superconducting circuits · DEMONSTRATED (Nature, 28 Jan 2026) (28 Jan 2026 (arXiv Mar 2025)) · 78 physical qubits · access: not cloud-accessible

architecture: Transmon lattice with tunable couplers · Open on the map

Register profile — the machine's variant of its architecture

qubit type: transmon

gate mechanism: tunable coupler

connectivity: 2-D lattice: 78 qubits with 137 couplers

control: room-temperature RF

control placement: room-temp

readout: dispersive

gate evidence: no published figure

flags: no published error rates

Technologies by layer — the machine's cell per layer

1 Qubit carrier	Transmon · primary ▣ Fig. 1a (optical micrograph, 78-qubit processor Chuang-tzu 2.0); Suppl. Fig. 8; §S3.B Device performance ✅ transmon, 78 qubits (CAS / Peking University); demonstration chip only, not cloud-accessible; no coherence published
2 Encoding	Bare physical qubit (no encoding) · primary ▤ §Experimental setup (anharmonicity −200 MHz ≫ hopping strength; two-level qubit subspace) 🔎 bare transmon \|0⟩/\|1⟩ subspace; family-determined, no machine-specific source
3 Gate mechanism	Tunable-coupler CZ / iSWAP · primary ▣ Fig. 1a (137 couplers linking all adjacent qubits); Suppl. Fig. 10b (coupler Z-pulse calibration); §S4 ✅ tunable-coupler gate assumed; gate mechanism and fidelities not published
4 Connectivity / transport	Static nearest-neighbour lattice · primary ▣ Fig. 1a (6-by-13 square lattice, 78 qubits, 137 couplers) ✅ connectivity not published; static nearest-neighbour lattice assumed
5 Control	Room-temperature electronics + per-qubit coax/flex · primary ▣ Suppl. Fig. 7 (room-temperature and cryogenic wiring); §S2 Experimental setup; §S4 Device control ✅ room-temperature RF control assumed (generic NISQ row); not published
6 Readout	Dispersive microwave readout (+TWPA, Purcell) · primary ▣ Suppl. Fig. 9c (readout resonator frequency distribution); Suppl. Fig. 7 (wiring); §S3.B ✅ dispersive readout; no readout fidelity published
7 Code	— none — nothing in this layer ▨ 🔎 no QEC code run; NISQ demonstration chip
8 Decoder	— none — nothing in this layer ▨ 🔎 no decoder; no QEC run
9 Interconnect	— none — nothing in this layer ▣ Fig. 1a (single monolithic 78-qubit chip); Suppl. Fig. 8 ✅ monolithic single 78-qubit chip, no interconnect
10 Manufacturing	Superconducting-qubit lithography (Al/AlOx/Al junctions, Nb wiring, 300 mm) · primary ▤ §S3.A Device fabrication ✅ superconducting-qubit lithography; family-determined, no machine-specific fab source

evidence: ✅ 7 / 10