用于量子計算的超導(dǎo)射頻+（SRF）結(jié)構(gòu)研究進展（演講PPT）-英

ThismanuscripthasbeenauthoredbyFermiResearchAlliance,

LLCunderContractNo.DE-AC02-07CH11359withtheU.S.

DepartmentofEnergy,OfficeofScience,OfficeofHighEnergy

Physics.

AdvancesinSRFcavityarchitecturesforquantumcomputing

TanayRoy

SQMSdivision,Fermilab

QuantumTechnologiesforFundamentalPhysicsWorkshop,Erice,Italy3Sep2023

Reportnumber:FERMILAB-SLIDES-23-283-SQMS

BasicRequirementsforaQuantumComputer

Measure

quantumstates

01

Quantumtwolevelsystems

|1〉

|0〉

Couplemultiplequbits

|1〉

|0〉

|1〉

|0〉

r0+β|1〉

Createarbitrarystates

Scalablearchitecture

2

TanayRoy-Fermilab

DifferentPlatforms

Trappedions

NIST

3TanayRoy-Fermilab

Superconductingcircuits

SQMS

NVcentersNMRNeutralatoms

chemie.tu

Photoniccrystals

Quantumdots

SuperconductingCircuits

JosephsonJunction

Losslessnonlinearinductor

I?I21/2

LJI=φ0

4

200nm

Transmon

TanayRoy-Fermilab

200μm

Transmon:AnharmonicOscillator

3

2

1

0

|2?

|1?

|0?

Qubit

HarmonicOscillatorAnharmonicOscillator

5TanayRoy-Fermilab

OperatingTemperature

|2?

f01≈

~

1

2πLJC

5GHz

KBT??f01

|1?

|0?

AnharmonicOscillator

~20nH

~50fF

20mK~240mK

6TanayRoy-Fermilab

Dilutionfridge~10mK

TraditionalMulti-qubitArchitecture

Qudit

Linearorplanargeometry

Computationalspace:2

Canwedobetter?

Scaling:d,d>2

9

UCSB,Nature519(7541)

TanayRoy-Fermilab

IBM

ProblemofRelaxation

Linearorplanargeometry

UCSB,Nature519(7541)

IBM

T1~100μs

10

Q:afew106

TanayRoy-Fermilab

Canwedobetter?

ZooofCavities

Nat.Phys.16,247Science342,6158

Yale,U.Pittsburgh

11

Weizmann

arXiv:2302.06442

Under

exploration

TanayRoy-Fermilab

PRL127,107701

U.Chicago,Rutgers

High-Q3DSRFCavities

T1>2s

1.3GHzSRF:

>1000timesbetterthan

transmons

T1>300ms

5GHzSRF:

Romanenkoetal.PRApplied13,034032

Q>1011at1K

Q>1010at10mK

12

TanayRoy-Fermilab

High-Q3DCavitiesasQudits

Qudit

2

T1>150ms

|10

T1>30ms

T1n>T11/n

I

3〉

〉

|2

1〉

|0

Romanenkoetal.PRApplied13,034032

1

T1>300ms

Stillmuchbetterthantransmonqubits

13TanayRoy-Fermilab

Transmonvs.CavityDrive

Qubit:a

0+β|1〉

Qudit:a0

0+a1

1+…+ad|d〉

Im(a)

歡

D(a)

Re(a)

15TanayRoy-Fermilab

QuditOperation

Im(a)

Im(a)

D(a=1)

0

Quantumstate

1喻eiπ1

a0

0+a1

1+…+ad|d〉

1喻eiπ1

a0

0__a1

1+…+ad|d〉

n喻eiθ

n

Selectivenumber-dependentarbitraryphase(SNAP)gate

PRL115,137002(2015)

Re(a)

Re(a)

16TanayRoy-Fermilab

UniversalGateSet

Im(a)

D(a)

SNAP

Cavitydrive

Unconditional

operationoncavity

Qudit:a0

0+a1

1+?+ad|d?

SNAPgate

八

Qudit:a0eiθ0

0+a1eiθ1

1+?+adeiθd|d?

Re(a)

Universalcontrol

Conditionaloperationon

cavityenabledbyatransmon

17TanayRoy-Fermilab

FirstMilestone

IncorporateTransmonintoa

TESLAcavity

18TanayRoy-Fermilab

FirstMilestone

IncorporateTransmonintoa

TESLAcavity

19TanayRoy-Fermilab

FirstMilestone

Achievedphotoncounting

543

2

1

0

IncorporateTransmonintoa

TESLAcavity

KeytoDarkMatterdetection

20TanayRoy-Fermilab

SecondMilestone

Preparequantumstates

τ≈0.95ms

21

3

2

1

0

3

2

1

0

TanayRoy-Fermilab

Wignertomography

Fock|1〉

Fock|2〉

ParityParity

1

0

-1

1.5

0.0

-1.5

MultquditArchitecture

Coupler

Manipulator

Transmon

Crosstalkissues

Fasterscaling:N>2N

All-to-allcoupling

Moderate-QcavitiesHigh-Q3Dcavities

Storage

CPU

BUS

RAM

22TanayRoy-Fermilab

Outlook

Improvesingle-celldevices

>Optimizetransmondesign,placement

>InvestigateotherSRFcavitygeometries

Scalingup

>Developmodulararc