RIKEN RQC-Fujitsu 64-qubit superconducting quantum computer

Raveh Neeman

doi:10.5281/zenodo.22674814

RIKEN RQC + Fujitsu · superconducting circuits · DEPLOYED (superseded by the 256-qubit machine, Apr 2025) (Oct 2023) · 64 physical qubits

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

Register profile — the machine's variant of its architecture

gate evidence: no published figure

flags: no published error rates, specification absent

Technologies by layer — the machine's cell per layer

1 Qubit carrier	Transmon · primary ▨ paragraph on the 64-qubit iteration 🔎 64-qubit superconducting machine launched Oct 2023 (MEXT support); transmon per the sibling and the 256-qubit successor
2 Encoding	Bare physical qubit (no encoding) · primary ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
3 Gate mechanism	— undisclosed — exists, nothing published ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
4 Connectivity / transport	Static nearest-neighbour lattice · primary ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
5 Control	Vertical (out-of-plane) signal delivery — VIO, coaxmon, 3D wiring · primary ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
6 Readout	Dispersive microwave readout (+TWPA, Purcell) · primary ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
7 Code	— none — nothing in this layer ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
8 Decoder	— none — nothing in this layer ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
9 Interconnect	— none — nothing in this layer ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration
10 Manufacturing	Superconducting-qubit lithography (Al/AlOx/Al junctions, Nb wiring, 300 mm) · primary ◌ 🔎 copied from the sibling riken-64q; the RIKEN page gives no design detail for the 64-qubit iteration

evidence: ✅ 0 / 10