Menno Veldhorst Operations on spin qubits 1 Last time from - - PowerPoint PPT Presentation

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Menno Veldhorst Operations on spin qubits 1 Last time from transistor Now quantum dot qubits To (many) quantum dots Split by magnetic field Initialize H 0 ~ S w i s zi reservoir readout empty dot filled dot spin down J.M. Elzerman, R.

SLIDE 1

Menno Veldhorst

Operations on spin qubits

SLIDE 2

Now quantum dot qubits Last time from transistor To (many) quantum dots

SLIDE 3

Initialize readout

Split by magnetic field empty dot filled dot spin down reservoir

J.M. Elzerman, R. Hanson, L.H. Willems van Beveren, B. Witkamp, L.M.K. Vandersypen, L.P.

Kouwenhoven. "Single-shot read-out of an individual electron spin in a quantum

dot." Nature 430, 431-435 (2004).

H0 ~ S wi szi

SLIDE 4

Ä

W W

250 μm

BAC BAC HRF ~ S Ai(t) cos(wi t) sxi

and control

SLIDE 5

F.H. Koppens, C. Buizert, K.J. Tielrooij, I.T. Vink, K.C. Nowack, T. Meunier, L.P. Kouwenhoven, L.M.K. Vandersypen. "Driven coherent oscillations of a single electron spin in a quantum dot." Nature 17, 766-771 (2006).

GaAs

HRF ~ S Ai(t) cos(wi t) sxi

SLIDE 6

5 10 15 20 25 30 0.0 0.2 0.4 0.6 0.8 τp (µs)

1 f

→

M. Veldhorst, J.C.C. Hwang, C.H. Yang, A.W. Leenstra, B. de Ronde, J.P. Dehollain, J.T.

Muhonen, F.E. Hudson, K.M. Itoh, A. Morello, A.S. Dzurak. "An addressable quantum dot qubit with fault-tolerant control-fidelity." Nature Nanotechnology 9, 981-985 (2014).

Silicon (28Si)

HRF ~ S Ai(t) cos(wi t) sxi

SLIDE 7

SLIDE 8

2 Qubits

Interaction off

HJ ~ S Jij (t) si · sj

D. Loss and D.P. DiVincenzo

"Quantum computation with quantum dots."

Phys. Rev. A 57, 120 (1998).

SLIDE 9

Interaction on

HJ ~ S Jij (t) si · sj

Interaction off

D. Loss and D.P. DiVincenzo

"Quantum computation with quantum dots."

Phys. Rev. A 57, 120 (1998).

2 Qubits

SLIDE 10

Larger Smaller

(2) (1)

(1) Tune tunnel coupling (2) Control detuning ε

SLIDE 11

Larger Smaller

(2) Control detuning ε (2)

M. Veldhorst, C.H. Yang, J.C.C. Hwang, W. Huang, J.P. Dehollain, J.T. Muhonen, S. Simmons,
A. Laucht, F.E. Hudson, K.M. Itoh, A. Morello, A.S. Dzurak. "A two-qubit logic gate in

silicon." Nature 526, 410-414 (2015).

SLIDE 12

Q1 |0 Y Uf Y UCZ00 Y Q2 |0 Y Y Y

A programmable two-qubit device in silicon

T.F. Watson, S.G.J. Philips, E. Kawakami, D.R. Ward, P. Scarlino, M. Veldhorst, D.E. Savage, M.G. Lagally, M. Friesen, S.N. Coppersmith, M.A. Eriksson, L.M.K. Vandersypen. "A programmable two-qubit quantum processor in silicon." Nature 555, 633-637 (2018).

Grover and Deutsch-Jozsa algorithms successfully implemented

SLIDE 13

Interfacing spin qubits with quantum dots

L.M.K. Vandersypen, H. Bluhm, J.S. Clarke, A.S. Dzurak, R. Ishihara, A. Morello, D.J. Reilly, L.R. Schreiber, M. Veldhorst. "Interfacing spin qubits in quantum dots and donors – hot dense, and coherent." npj Quantum Information 3, 34 (2017).