Quantum Communications in space using satellites Giuseppe Vallone , - - PowerPoint PPT Presentation

Quantum Communications in space using satellites

Giuseppe Vallone, D. Bacco, D. Dequal, S. Gaiarin, M. Schiavon, M. Tomasin, V. Luceri, G. Bianco and P . Villoresi "Fundamental and Quantum Physics with Lasers" Workshop LNF - Frascati, 23 October 2014

Intro QC Results QKD Perspectives Conclusions

Summary

1

Introduction and motivations

2

Quantum communication in space

3

Results

4

QKD scheme

5

Perspectives

6

Conclusions

• Pag. 2

Intro QC Results QKD Perspectives Conclusions

Summary

1

Introduction and motivations

2

Quantum communication in space

3

Results

4

QKD scheme

5

Perspectives

6

Conclusions

• Pag. 3

Intro QC Results QKD Perspectives Conclusions

What is Quantum Communication?

I Quantum Communications is the

ability of faithful transmit quantum states between two distant locations

I Ground QC have progressed up to

commercial stage using fiber-cables

I Quantum Communications on

planetary scale require complementary channels including ground and satellite links

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Intro QC Results QKD Perspectives Conclusions

Motivation

Why free-space quantum communications?

• Pag. 5

Intro QC Results QKD Perspectives Conclusions

Motivation

Why free-space quantum communications?

I Creation of a worldwide quantum

network: overcome fiber-loss limitations

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Intro QC Results QKD Perspectives Conclusions

Motivation

Why free-space quantum communications?

I Creation of a worldwide quantum

network: overcome fiber-loss limitations

I Explore the limits of Quantum

Mechanics and quantum correlations over very long distances

• Pag. 5

Intro QC Results QKD Perspectives Conclusions

Context

I On May 24, 2014 Japan’s NICT launched SOTA on

Socrates satellite.

I Ongoing programs for QC on satellite in China and

Canada as well as in Singapore and USA.

• Pag. 6

Intro QC Results QKD Perspectives Conclusions

Summary

1

Introduction and motivations

2

Quantum communication in space

3

Results

4

QKD scheme

5

Perspectives

6

Conclusions

• Pag. 7

Intro QC Results QKD Perspectives Conclusions

Timeline

UniPD Space QComms

University of Padova operated at Matera Laser Ranging Observatory, owned by the Italian Space Agency and directed by Dr. Giuseppe “Pippo” Bianco.

• P. Villoresi et al.

New J. Phys. 10 033038 (2008)

• Pag. 8

Intro QC Results QKD Perspectives Conclusions

Objectives

I To simulate a quantum source in

Space using orbiting retroreflectors

I To demonstrate the measurement

• f quantum states in the downlink

I To address the mitigation of the

background noise

I To demonstrate quantum

communication of a generic qubits from Space to ground

I To envisage the exploitation of this

type of link

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Intro QC Results QKD Perspectives Conclusions

MLRO facility

Matera Laser Ranging Observatory (MLRO): 1.5 m telescope with millimeter resolution in SLR research hub for Space QC since 2003 Dome Laser

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Intro QC Results QKD Perspectives Conclusions

The making of the qubits

I Source on satellite simulated by a CCR I Source (Alice) need to be at the single

photon level

I Downlink attenuation from ⇠ 3 cm LEO

sources in the range of 55-70 dB.

I Short pulses necessary for background

rejection

I Not too short to prevent bandwidth

• pening and noise increasing

CCR: Corner-Cube Retroreflector

• Pag. 11

Intro QC Results QKD Perspectives Conclusions

The making of the qubits

I MLRO master laser provided the solution:

100 MHz, 100 ps, 300 mW, 1064 nm

I Second harmonics needed for qubits I First order (6.2 µm) PPLN I MgO doped Congruent Lithium Niobate -

50 mm – thermally stabilized.

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Intro QC Results QKD Perspectives Conclusions

Setup

• Pag. 13
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

Coudé path of in-and-out

I Characterization of

the polarization transformation

I Assessment of

total transmission efficiency

I Mutual alignement

• f SLR and Qubit

beams

• Pag. 14
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

Measuring the qubits

I The Coudé path is used in both

directions for both the SLR beam and the qubits

I The upward and inward beams are

combined using a non polarizing beam splitter (BS)

I Two large ares SPADs mounted to

the exit ports, designed to address the velocity-aberration

I 81 ps timetagging of 8 channels

• Pag. 15
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

Summary

1

Introduction and motivations

2

Quantum communication in space

3

Results

4

QKD scheme

5

Perspectives

6

Conclusions

• Pag. 16
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

Single passage of LARETS

Orbit height 690 km - spherical brass body 24 cm in diameter, 23 kg mass, 60 Metallic coated Corner-Cube Retroreflectors

Apr 10th, 2014, start 4:40 am CEST

50 100 150 200 250 300 1,000 1,200 1,400 1,600 −2 −1 1 2 20 10 10 20 −2 −1 1 2 −2 −1 1 2 −2 −1 1 2 ∆=t meas−t ref (ns) Time (s) Counts Satellite distance (km)

Det| H ⟩ Det| V ⟩ Det| H ⟩ Det| V ⟩ Det | L⟩ Det| R⟩ Det| L⟩ Det| R⟩

|H⟩ |V ⟩ |L⟩ |R⟩

Detection of four polarization states received from satellite 10 s windows: arrival time within 0.5ns from predictions

• Pag. 17
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

Link Budget and photon return rate

Radar equation for the prediction of detected number of photons per pulse UPLINK µsat = µtx ηtx GtρAeff Σ ✓ 1 4πR2 ◆ Ta DOWNLINK µrx = µsat Σ ρAeff ✓ 1 4πR2 ◆ TaAtηrxηdet Radar equation model provides a precise fit for the measured counts and the µsat value for the different satellites

Frequency (Hz)

1,600 2,100 2,600 10

1

10

2

10

3

10

4

10

5

Ajisai

1,600 2,100 2,600 10

1

10

2

10

3

10

4

10

5

Jason−2

1,000 1,400 1,800 10

1

10

2

10

3

10

4

10

5

Larets

Satellite distance (km)

1,000 1,400 1,800 10

1

10

2

10

3

10

4

10

5

Starlette Stella

• Pag. 18
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

QBER: Quantum Bit Error Rate

Ajisai Non polarization maintaining CCR: Polarization Q-Comm not possible Jason-2, Larets, Starlette, Stella Polarization maintaining CCR:

I QBER compatible with applications I Demonstration of stable QBER over

extended link duration

50 100 Qd=39.2±0.8%

Qn=39.2±0.8% µ=3,432±42 ¯ f=(1,964±24)Hz

Ajisai

10 20 30 Qd=6.0±1.4%

Qn=1.8±0.1% µ=1.8±0.1 ¯ f=(100±6)Hz

Jason−2

10 20 30 Qd=1.2±0.1%

µ=4.4±0.5 ¯ f=(112±13)Hz

Quantum Bit Error Rate (%)

Larets

10 20 30 Qd=4.3±1.2%

Qn=3.4±1.0% µ=2.6±0.2 ¯ f=(346±21)Hz

Starlette

10 20 30 10 20 30 Qd=6.8±2.3%

Qn=5.0±1.9% µ=1.3±0.1 ¯ f=(149±15)Hz

Elapsed time (s)

Stella

• Pag. 19
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

Summary

1

Introduction and motivations

2

Quantum communication in space

3

Results

4

QKD scheme

5

Perspectives

6

Conclusions

• Pag. 20
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

QKD: quantum key distribution

I A novel approach towards unconditionally secure

communications

I Exploit quantum mechanics laws for establishing secure

keys

I Single photon transmission for create keys and classical

channel for send encrypted message

• Pag. 21
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

New QKD satellite protocol using retroreflectors

On the base of this experiment, we propose a two-way QKD protocol for space channels:

• Pag. 22
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

New QKD satellite protocol using retroreflectors

On the base of this experiment, we propose a two-way QKD protocol for space channels:

I In the ground station, a linearly polarized train of pulses

is injected in the Coudé path

• Pag. 22
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

New QKD satellite protocol using retroreflectors

On the base of this experiment, we propose a two-way QKD protocol for space channels:

I In the ground station, a linearly polarized train of pulses

is injected in the Coudé path

I The beam is directed toward a satellite with CCRs having

a Faraday Rotator (or equivalent), that rotate the returning polarization by θ, according to QKD protocol

• Pag. 22
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

New QKD satellite protocol using retroreflectors

On the base of this experiment, we propose a two-way QKD protocol for space channels:

I In the ground station, a linearly polarized train of pulses

is injected in the Coudé path

I The beam is directed toward a satellite with CCRs having

a Faraday Rotator (or equivalent), that rotate the returning polarization by θ, according to QKD protocol

I A measure of the intensity of the incoming beam avoid

Trojan horse attack

• Pag. 22
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

New QKD satellite protocol using retroreflectors

On the base of this experiment, we propose a two-way QKD protocol for space channels:

I In the ground station, a linearly polarized train of pulses

is injected in the Coudé path

I The beam is directed toward a satellite with CCRs having

a Faraday Rotator (or equivalent), that rotate the returning polarization by θ, according to QKD protocol

I A measure of the intensity of the incoming beam avoid

Trojan horse attack

I In the CCR a suitable attenuator lowers the mean photon

number to the single photon level

• Pag. 22
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

New QKD satellite protocol using retroreflectors

On the base of this experiment, we propose a two-way QKD protocol for space channels:

I In the ground station, a linearly polarized train of pulses

is injected in the Coudé path

I The beam is directed toward a satellite with CCRs having

a Faraday Rotator (or equivalent), that rotate the returning polarization by θ, according to QKD protocol

I A measure of the intensity of the incoming beam avoid

Trojan horse attack

I In the CCR a suitable attenuator lowers the mean photon

number to the single photon level

I The state measure is done as in present experiment

• Pag. 22
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

New QKD satellite protocol using retroreflectors

The two-way QKD protocol:

I By this scheme, a decoy state BB84 protocol can be

realised between satellite and ground

I Such protocol is currently realizable using few centimeter

retroreflector as optical part in orbit

• Pag. 23
• G. Vallone et al., Experimental Satellite Quantum Communications, [arXiv:1406.4051]

Intro QC Results QKD Perspectives Conclusions

Summary

1

Introduction and motivations

2

Quantum communication in space

3

Results

4

QKD scheme

5

Perspectives

6

Conclusions

• Pag. 24

Intro QC Results QKD Perspectives Conclusions

Long term opportunities

Unique opportunity of Quantum Physics in Space Possibility of testing quantum physics in new environment and probing the laws of nature at very large distance

• Pag. 25

Intro QC Results QKD Perspectives Conclusions

Long term opportunities

Unique opportunity of Quantum Physics in Space Possibility of testing quantum physics in new environment and probing the laws of nature at very large distance

I Distribution of entanglement from Earth to Space I Test of Bell’s Inequalities with unprecedented conditions:

LEO or GEO-orbit, moving terminals, gravitational field

• Pag. 25

Intro QC Results QKD Perspectives Conclusions

Long term opportunities

Unique opportunity of Quantum Physics in Space Possibility of testing quantum physics in new environment and probing the laws of nature at very large distance

I Distribution of entanglement from Earth to Space I Test of Bell’s Inequalities with unprecedented conditions:

LEO or GEO-orbit, moving terminals, gravitational field

I Teleportation from Earth to Space I Quantum technologies in long distance applications

• Pag. 25

Intro QC Results QKD Perspectives Conclusions

Long term opportunities

Unique opportunity of Quantum Physics in Space Possibility of testing quantum physics in new environment and probing the laws of nature at very large distance

I Distribution of entanglement from Earth to Space I Test of Bell’s Inequalities with unprecedented conditions:

LEO or GEO-orbit, moving terminals, gravitational field

I Teleportation from Earth to Space I Quantum technologies in long distance applications I Test of foundations of quantum field theory and general

relativity

• Pag. 25

Intro QC Results QKD Perspectives Conclusions

Entanglement distribution

I Quantum Entanglement is, according to

Erwin Schrodinger, the “characteristic trait

• f quantum mechanics”

I Entanglement is a unique resource for

Quantum Information applications (teleportation, dense coding, etc..) |ψiAB 6= |φiA ⌦ |χiB A B |ψiAB

• Pag. 26

Intro QC Results QKD Perspectives Conclusions

Entanglement distribution

I Quantum Entanglement is, according to

Erwin Schrodinger, the “characteristic trait

• f quantum mechanics”

I Entanglement is a unique resource for

Quantum Information applications (teleportation, dense coding, etc..) |ψiAB 6= |φiA ⌦ |χiB A B |ψiAB

I Limits on the distance between two entangled systems? I Is entanglement limited to certain mass and length scales

• r altered under specific gravitational circumstances?
• Pag. 26

Intro QC Results QKD Perspectives Conclusions

Entanglement distribution

Photons are the ideal candidate for distributing entanglement

I Easy to generate entangled photons

• I Photons can travel over long distances without

decoherence

• Pag. 27

Intro QC Results QKD Perspectives Conclusions

Bell’s test

If a set of correlation do not satisfy the Bell’s inequality S  2, the correlations cannot be explained by a local realistic theory.

• Pag. 28

Intro QC Results QKD Perspectives Conclusions

Bell’s test

If a set of correlation do not satisfy the Bell’s inequality S  2, the correlations cannot be explained by a local realistic theory.

I Bell’inequality violated between fixed location: "spooky

action at distance" at speed greater than 104c.

• Pag. 28

Intro QC Results QKD Perspectives Conclusions

Bell’s test

If a set of correlation do not satisfy the Bell’s inequality S  2, the correlations cannot be explained by a local realistic theory.

I Bell’inequality violated between fixed location: "spooky

action at distance" at speed greater than 104c.

I Bell’s test with moving terminals

1 1x 2y 2 2 1

t Test of Test of S S t z z

• Pag. 28

Intro QC Results QKD Perspectives Conclusions

Summary

1

Introduction and motivations

2

Quantum communication in space

3

Results

4

QKD scheme

5

Perspectives

6

Conclusions

• Pag. 29

Intro QC Results QKD Perspectives Conclusions

Conclusions

I We have experimentally demonstrated Quantum

Communication from several satellites acting as quantum transmitter and with MLRO as the receiver

• Pag. 30

Intro QC Results QKD Perspectives Conclusions

Conclusions

I We have experimentally demonstrated Quantum

Communication from several satellites acting as quantum transmitter and with MLRO as the receiver

I QBER was found low enough to demonstrate the feasibility

• f quantum information protocols such as QKD along a

Space channel

• Pag. 30

Intro QC Results QKD Perspectives Conclusions

Conclusions

I We have experimentally demonstrated Quantum

Communication from several satellites acting as quantum transmitter and with MLRO as the receiver

I QBER was found low enough to demonstrate the feasibility

• f quantum information protocols such as QKD along a

Space channel

I The ability of propagating quantum correlation over large

distance will have a great impact for fundamental physics and quantum information applications

• Pag. 30

Intro QC Results QKD Perspectives Conclusions

REFERENCES

I G. Vallone, D. Bacco, D. Dequal, S. Gaiarin, V. Luceri, G. Bianco, P

. Villoresi, Experimental Satellite Quantum Communications, [arXiv:1406.4051]

I P

. Villoresi, et al., Experimental verification of the feasibility of a quantum channel between space and Earth, New J. Phys. 10, 033038 (2008)

I C. Bonato, et al., Feasibility of satellite quantum key distribution, New J.

• Phys. 11, 045017 (2009)

I A. Tomaello, et al., P

. Link budget and background noise for satellite quantum key distribution Adv. Sp. Res. 47, 802 (2011)

I D. Rideout, et al., Fundamental quantum optics experiments

conceivable with satellites reaching relativistic distances and velocities

• Class. Quantum Gravity 29, 224011 (2012)
• Pag. 31