© 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