A fault-tolerant addressable spin qubit in a natural silicon quantum dot

Abstract

This is the first experimental demonstration of a fault-tolerant spin qubit in industry-compatible isotopically natural silicon.

Entangling distant resonant exchange qubits via circuit quantum electrodynamics

“…23,[62][63][64][65][66][67] However, the valley degree of freedom in Si leads to a more complex low-energy spectrum than that of GaAs. Thus, a direct extension of RX qubit properties to Si is not obviously straightforward.…”

“…[42][43][44][45][46][47][48] An analogous approach has been investigated for hybrid solid-state quantum systems consisting of semiconductor charge [49][50][51][52][53][54] or spin 49,55-61 qubits coupled to a superconducting resonator. The potentially longer coherence times possible for spin qubits, particularly in silicon, 23,[62][63][64][65][66][67] in comparison to superconducting qubits and quantum dot charge qubits are advantageous for achieving the strong coupling regime, in which the interaction rate exceeds both the qubit and cavity decay arXiv:1603.04829v1 [cond-mat.mes-hall] 15 Mar 2016 rates.…”

A CMOS silicon spin qubit

“…In natural silicon, however, the hyperfine interaction is weaker, being due to the ≈4.7% content of 29 Si, the only stable isotope with a non-zero nuclear spin. Measured values range between 50 ns and 2 μs (refs 10, 11, 12, 13, 14). Experiments carried out on electron spin qubits in isotopically purified silicon (99.99% of spinless 28 Si) have even allowed extending to 120 μs (ref.…”

Spin-selective electron transfer in a quantum dot array

“…These are two figures of merit that are highly desirable for a scalable quantum computing architecture. Various types of qubit operations have been demonstrated [10][11][12], including two-qubit logic gates using the exchange interaction between single spins in isotopically enriched silicon [13]. On the other hand, single-electron pumps [14][15][16][17][18][19][20] and the shuttling of single electron [21,22] in quantum dots have also been demonstrated at metrological accuracy.…”

“…In this paper, we propose a scheme for spin-selective coherent electron transfer in a quantum dot array achievable using the proven experimental techniques in single-spin shuttling [21,22] in a silicon qubit architecture [11][12][13]. The gradient of oscillating magnetic fields and controlled gate voltages are utilized to separate the electron wave function into different quantum dots in a spin-selective manner.…”