Operation of a silicon quantum processor unit cell above one kelvin

Chih Heng Yang, Ross Leon, Jason Hwang, Andre Saraiva, Tuomo Tanttu, Wister Huang, Julien Camirand Lemyre, Kok Wai Chan, Kuan Tan, Fay E. Hudson, Kohei Itoh, Andrea Morello, Michel Pioro-Ladriere, Arne Laucht, Andrew Dzurak

Research output: Contribution to journalArticleScientificpeer-review

34 Citations (Scopus)
14 Downloads (Pure)

Abstract

Quantum computers are expected to outperform conventional computers in several important applications, from molecular simulation to search algorithms, once they can be scaled up to large numbers—typically millions—of quantum bits (qubits). For most solid-state qubit technologies—for example, those using superconducting circuits or semiconductor spins—scaling poses a considerable challenge because every additional qubit increases the heat generated, whereas the cooling power of dilution refrigerators is severely limited at their operating temperature (less than 100 millikelvin). Here we demonstrate the operation of a scalable silicon quantum processor unit cell comprising two qubits confined to quantum dots at about 1.5 kelvin. We achieve this by isolating the quantum dots from the electron reservoir, and then initializing and reading the qubits solely via tunnelling of electrons between the two quantum dots. We coherently control the qubits using electrically driven spin resonance in isotopically enriched silicon. Si, attaining single-qubit gate fidelities of 98.6 per cent and a coherence time of 2 microseconds during ‘hot’ operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures. Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 tesla, corresponding to a qubit control frequency of 3.5 gigahertz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full-scale silicon quantum computer and satisfies layout constraints required by error-correction architectures. Our work indicates that a spin-based quantum computer could be operated at increased temperatures in a simple pumped 4He system (which provides cooling power orders of magnitude higher than that of dilution refrigerators), thus potentially enabling the integration of classical control electronics with the qubit array.
Original languageEnglish
Pages (from-to)350-354
JournalNature
Volume580
Issue number7803
DOIs
Publication statusPublished - 15 Apr 2020
MoE publication typeA1 Journal article-refereed

Fingerprint Dive into the research topics of 'Operation of a silicon quantum processor unit cell above one kelvin'. Together they form a unique fingerprint.

Cite this