© Hitachi Europe Ltd. 2014. All rights reserved.
SiQIP 2015, Cambridge 11 Sept. 2015
A.C. Betz1, R. Wacquez2, M. Vinet2, M. Sanquer2, A.J. Ferguson3, M.F. Gonzalez-Zalba1
1 Hitachi Cambridge Laboratory, Cambridge, UK 2 CEA-LETI, Grenoble, France 3 Cavendish Laboratory, Cambridge, UK
Towards a CMOS Quantum Computing Architecture
The next step: Integrated Quantum Circuits
Veldhorst, arxiv411.5760v1 (2015) Pla, Nature 496, 334 (2013) Weber, Nature Nano. 9, 430 (2014) Kim, Nature 511, 70 (2014)
transistor
integrated circuit
Silicon QIP
How to integrate these qubits into CMOS?
today’s semiconductor industry is compatible with
Can we use Moore’s Law to our advantage?
A compact double QD A charge motion sensor Spin state detection
Gonzalez-Zalba, Nature Comm. (2015) Betz, Nano Letters (2015)
Can we use Moore’s Law to our advantage?
Spin Qubits In
Silicon Corner State Quantum Dots
Gonzalez-Zalba et al., Nature Comm. 6 6084
CMOS Double quantum dot
Voisin et al., Nano Letters 14 2094
corner state W=100 nm, L= 60 nm, Sgg= 70 nm
A. Andreev, D. Williams (Hitachi) FDSOI transistor
Independent control of corner dots
VG1(V) VG2(V)
G1 G2
lever arms α ≈ 0.3
multi-electron regime
Coupled double quantum dot
G1 G2
VG
1(V
)
VG2(V) individually and independently control two coupled quantum dots
fabricated in an industry-standard CMOS transistor
Dispersive & dissipative RF gate readout
30mK
Vds
At the resonant frequency: Dissipation in the system (Γ) Quantum or tunnelling capacitance (Φ)
I Q
𝒇𝒄 =𝟏
𝟐𝝅 𝑳𝑪𝒕𝒐𝒕
Highly sensitive readout: charge sensitivity as low as
δq=37μe/Hz1/2
at 8MHz bandwidth
Phase resolution down to 0.1mrad ~ 0.1aF
Gonzalez-Zalba et al., Nature Comm. 6 6084 (2015)
Dispersive readout detects charge motion
QD1 QD2
• Strong coupling: RF gate – QD2 → 1 set of lines
• QD2 coupled to charge transitions in separate object → kinks → coupling to QD1
Dispersive readout senses capacitance changes
Sisyphus Mechanism: Tunnelling Capacitance1
Quantum Capacitance2
1) Gonzalez-Zalba, Betz et al., Nature Comm 6 6084
2) Betz et al., Nano Letters 15(7), 4622 (2015)
Magnetic Field dependence
(2,0)
(1,1)
Pauli Spin Blockade
(2,0)
(1,1)
B=0 B=0
B>0
(2,0)
(1,1)
magnetic field
Line shape analysis – Tunnel coupling
Tunnel Coupling t = 80 µeV
(2,0)
(1,1)
Field dependence follows thermal distribution
(2,0)
(1,1) B>0
𝐶𝑞 ∝ 𝑃𝑠𝑔 − 𝑃𝑠𝑒 = 𝑒𝑡/𝑘𝑇 − 𝑒−𝑡/𝑘𝑇
𝑍(𝑇𝑒 , 𝑡)
Singlet-triplet blockade lifting
Singlet-triplet blockade lifting
Singlet-triplet blockade lifting
Conclusions
• Independent control of corner state quantum dots in Si FET
• Dispersive readout of double quantum in few electron regime
• Observation of spin blockade in even parity transition
• Discerned singlet and triplet branches in magnetic field study
Outlook: Towards a CMOS spin qubit architecture
Urdampilleta, PRX 5, 031024 (2015) Poster 15 Betz, Nano Letters 15(7), 4622 (2015)
Silicon CMOS is compatible with QIP
Outlook: Towards a CMOS spin qubit architecture
MOS-based Quantum Information Technology Singlet-Triplet DQD Singlet-Triplet QD-donor
Donor spin QD spin DQD hybrid
2(+) qubit structures
peripherial
integraed
control electronics
Silicon CMOS is compatible with QIP
Partners: CEA-LETI, UCL , UCPH, Hitachi, EPFL, CNR, VTT
Thank you for your attention
Fernando Gonzalez-Zalba
Marc
Sanquer
Andrew Ferguson
Maud
Vinet Romain
Wacquez
Xavier
Jehl
