MTC2018 - Communication Technologies in the Age of Quantum Information: The Quantum Internet

Speaker: Shota Nagayama

In this session, Nagayama will discuss telecommunications in the age of quantum information. The quantum internet operates on a different principle—quantum mechanics—from the internet we have today, on the foundation of entanglement created between two random nodes. Naturally, the quantum internet comes with different advantages. For example, it is the foundation for realizing completely secure cryptography. Furthermore, quantum computers utilize entanglement and superposition to simultaneously handle a mass of states. Due to this feature, quantum memory size is crucial. By connecting quantum computers via telecommunications to conduct distributed quantum computing, we can obtain a higher computing ability. Entanglement is the fundamental physical attribute of quantum mechanics, and therefore is also useful for a variety of scientific experiments. Nagayama will also touch on the current progress of research and development of the quantum internet. We hope this session will give you a chance to think a bit about the future of telecommunications.

Transcript

1. Shota Nagayama R4D Senior Researcher Communication Technologies in the Age of Quantum Information: The Quantum Internet
2. Communication Technologies in the Age of Quantum Information: The Quantum Internet
3. R4D Senior Researcher Shota Nagayama
4. Research for Design Development Deployment Disruption An R&D organization aiming for disruption by implementing technology in society What is R4D? Research Areas • AI/ML • Blockchain • Computer Network • Energy • Internet Governance • Logistics • Robotics • Robot and Sociality • Quantum Computing ◦ Quantum Internet ◦ Circuit-based QC ◦ Quantum Annealing • Satellite Data • XR(AR/VR/MR)
5. Where quantum internet stands in R4D’s research • Classical computers have significantly advanced communication abilities. We need to act on the assumption that quantum computing will do the same. ◦ Investing in research for new infrastructure • How is this related to Mercari, Merpay, etc.? ◦ We need to set security standards for the coming quantum era, or else we can’t trust the internet as a platform for economic activity.
6. Today’s Topics • What is quantum computing? • Quantum key distribution networks with trusted nodes ◦ Quantum networks for classical computers • The true quantum internet through quantum relays ◦ Quantum networks for quantum computers
7. Today’s Topics • What is quantum computing? • Quantum key distribution networks with trusted nodes ◦ Quantum networks for classical computers • The true quantum internet through quantum relays ◦ Quantum networks for quantum computers
8. What is quantum computing? Each probability is represented with a complex amplitude (and therefore interference occurs) With superposition, there is a probability for each state Converge on the answer to the problem n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 A set of quantum bits can have states
9. With superposition, there is a probability for each state n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 The speed of this step determines the computing speed What is quantum computing? A set of quantum bits can have states Converge on the answer to the problem Each probability is represented with a complex amplitude (and therefore interference occurs)
10. The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing Half 0, half 1 Mostly 0, but a little 1 Mostly 1, but a little 0 ・・・ Classical computing 0 1
11. The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing Superposition of quantum states { ・・・ 0 1 Classical computing Half 0, half 1 Mostly 0, but a little 1 Mostly 1, but a little 0
12. The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing 0 1 { ・・・ Classical computing Half 0, half 1 Mostly 0, but a little 1 Mostly 1, but a little 0 Superposition of quantum states Quantum World
13. The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing 0 1 { ・・・ Classical computing Half 0, half 1 Mostly 0, but a little 1 Mostly 1, but a little 0 Superposition of quantum states Quantum World Measurement by those of us in the classical world
14. Mostly 1, but a little 0 Mostly 0, but a little 1 The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing 0 1 { ・・・ Becomes one of these two states (projection to a classical state) Superposition of quantum states Classical computing Half 0, half 1
15. What is quantum computing? Each probability is represented with a complex amplitude (and therefore interference occurs) With superposition, there is a probability for each state Converge on the answer to the problem n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 A set of quantum bits can have states Quantum World Final measurement
16. Quantum state formula The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing { ・・・ Basis vector Basis vector Superposition of quantum states Half 0, half 1 Mostly 0, but a little 1 Mostly 1, but a little 0
17. Quantum state formula The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing { ・・・ How 0-ish it is (complex) How 1-ish it is (complex) Superposition of quantum states Half 0, half 1 Mostly 0, but a little 1 Mostly 1, but a little 0 Basis vector Basis vector
18. Quantum state formula The Wonders of Quantum Computing (and Quantum Mechanics): #1 No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! 0 1 Quantum computing { ・・・ How 0-ish it is (complex) How 1-ish it is (complex) Common notation Superposition of quantum states Half 0, half 1 Mostly 0, but a little 1 Mostly 1, but a little 0 Basis vector Basis vector
19. • Interference Quantum gate causes interference original state final state No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! The Wonders of Quantum Computing (and Quantum Mechanics): #2 Due to interference, goes away
20. What is quantum computing? Each probability is represented with a complex amplitude (and therefore interference occurs) With superposition, there is a probability for each state Converge on the answer to the problem n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 A set of quantum bits can have states
21. • Quantum entanglement 2 quantum states Can be separated (obviously, because they’re different) Can be separa--huh?! => Quantum entanglement 　 ？ 　 ？ 25% 4 bases for 2 quantum states 25% 25% 25% 50% 0% 0% 50% No one knows why it’s like this, but it’s a natural phenomenon, so why let it go to waste? Let’s use it! The Wonders of Quantum Computing (and Quantum Mechanics): #3
22. What is quantum computing? Each probability is represented with a complex amplitude (and therefore interference occurs) With superposition, there is a probability for each state Converge on the answer to the problem n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 A set of quantum bits can have states
23. Some Quantum Algorithms • Using the quantum properties as they are: Superpolynomial speedup ◦ Quantum simulation -> drug design, materials development • Exploiting the structure of problems: Superpolynomial speedup ◦ Factoring, discrete-log problems, semidefinite programming, pattern matching, PCA, etc. • Generally using interference: Polynomial speedup ◦ Finding inverse functions, etc. • http://math.nist.gov/quantum/zoo/ • https://www.qmedia.jp/tag/quantum-algorithm/
24. With superposition, there is a probability for each state n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 The speed of this step determines the computing speed What is quantum computing? A set of quantum bits can have states Converge on the answer to the problem Each probability is represented with a complex amplitude (and therefore interference occurs)
25. Today’s Topics • What is quantum computing? • Quantum key distribution networks with trusted nodes ◦ Quantum networks for classical computers • The true quantum internet through quantum relays ◦ Quantum networks for quantum computers
26. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob State chosen at random
27. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob State chosen at random
28. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob Eve State chosen at random
29. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob Eve State chosen at random
30. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob Eve State chosen at random Quantum World
31. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob Eve Observation State chosen at random
32. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob Eve 0 Makes a bad copy of the wrong state State chosen at random Observation
33. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob 0 Discrepancy State chosen at random
34. 0 1 Half 0, half 1 (phase is +) What is quantum key distribution? Half 0, half 1 (phase is -) Alice Bob 0 Discrepancy By comparing part of the key, you can determine the presence of a third-party intercepter State chosen at random
35. Quantum communication (and some issues with it) • Communication that stores information in photons • Loss of optical signal = loss of photons = loss of quantum information • Because everything is hidden behind the wall to the quantum world, signals can’t be amplified, which means signals can’t be sent across long distances.
36. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob
37. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob
38. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob
39. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob
40. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob
41. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob
42. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob
43. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob Eve
44. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob Eve
45. Quantum key distribution networks with trusted nodes • Limit quantum communication to one hop only • The keys for each link are created with quantum key distribution • Quantum key distribution is done securely on the classical internet (key encapsulation) • This assumes you can trust all nodes, hence the name “trusted nodes” Quantum key distribution device Quantum key distribution Quantum key distribution Quantum key distribution Alice Bob Eve
46. Quantum key distribution networks with trusted nodes: Large-scale experiments http://iopscience.iop.org/article/10.1088/1367-2630/11/7/075001 http://www.ntt.co.jp/news2010/1010/101014a_1.html https://medium.com/@ASMLcompany/start-your-engines-the-race-to-quantum-computing-is-on-14c3076a5c47 China: Quantum Backbone spanning 2000km (Connecting Beijing, Jinan, Hefei, and Shanghai) Japan: Tokyo QKD Network (2010) The SECOQC quantum key distribution network in Vienna (2008)
47. Today’s Topics • What is quantum computing? • Quantum key distribution networks with trusted nodes ◦ Quantum networks for classical computers • The true quantum internet through quantum relays ◦ Quantum networks for quantum computers
48. Quantum internet through quantum relays • Security (completely secure encrypted communication, etc.) ◦ Quantum key distribution, quantum signatures, quantum authentication, hidden quantum computing, etc. • Quantum sensor networks ◦ Time synchronization, very-long-baseline interferometry, etc. • Distributed quantum computing ◦ Exponentially speed up quantum computing
49. How quantum internet works Creates quantum entanglement Creates quantum entanglement Creates quantum entanglement Quantum repeater • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays
50. Quantum teleportation Quantum entanglement Quantum A Quantum B Quantum C CNOT gate
51. Some sort of parity measurement Quantum teleportation CNOT gate Quantum A Quantum B Quantum entanglement Quantum C
52. Some sort of parity measurement Quantum teleportation CNOT gate Quantum A Quantum B Quantum C
53. Shows the results of the measurement Some sort of parity measurement Quantum teleportation CNOT gate Quantum A Quantum B Quantum C
54. Some sort of parity measurement Quantum teleportation CNOT gate The state of quantum A shows up in C! It doesn’t matter how far apart B and C are. Quantum A Quantum B Quantum C Shows the results of the measurement
55. Some sort of parity measurement The state of quantum A shows up in C! It doesn’t matter how far apart B and C are. →We want to send Quantum A. 　But we don’t want to lose A, so 　when in an environment where loss is possible 　(fiber, etc.), we create quantum entanglement 　between B and C, and then send A 　using quantum teleportation. Quantum teleportation CNOT gate Quantum A Quantum B Quantum C Shows the results of the measurement
56. How quantum internet works Creates quantum entanglement Creates quantum entanglement Creates quantum entanglement Quantum repeater • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays
57. How quantum internet works Quantum entanglement We want this state! • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays Quantum repeater
58. How quantum internet works Creates quantum entanglement Creates quantum entanglement Creates quantum entanglement Quantum repeater • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays • The result of the measurement is sent to the end node using the classical internet, and the qubit receives feedback Some sort of parity measurement Some sort of parity measurement
59. How quantum internet works Quantum entanglement • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays • The result of the measurement is sent to the end node using the classical internet, and the qubit receives feedback Quantum repeater
60. How quantum internet works (routing) • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays • The result of the measurement is sent to the end node using the classical internet, and the qubit receives feedback Quantum repeater
61. How quantum internet works (routing) • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays • The result of the measurement is sent to the end node using the classical internet, and the qubit receives feedback Quantum repeater
62. How quantum internet works (routing) • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays • The result of the measurement is sent to the end node using the classical internet, and the qubit receives feedback Quantum repeater Some sort of parity measurement Some sort of parity measurement
63. How quantum internet works (routing) • A network that creates quantum entanglement between arbitrary nodes • The intermediary nodes are quantum relays • The result of the measurement is sent to the end node using the classical internet, and the qubit receives feedback We can create quantum entanglement between two arbitrary nodes! Quantum repeater
64. With superposition, there is a probability for each state n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 The speed of this step determines the computing speed What is quantum computing? A set of quantum bits can have states Converge on the answer to the problem Each probability is represented with a complex amplitude (and therefore interference occurs)
65. n=4 n=5……. n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 0000 0001 Even if you increase n with distributed quantum computing, A set of quantum bits can have states
66. Wave interference due to quantum algorithms Even if you increase n with distributed quantum computing, if it’s fast enough, you can still do it! n=4 n=5……. n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 0000 0001 A set of quantum bits can have states
67. Wave interference due to quantum algorithms Even if you increase n with distributed quantum computing, if it’s fast enough you can still do it! n=4 n=5……. n=1 n=2 n=3 0 00 01 000 001 010 011 1 10 11 100 101 110 111 0000 0001 A set of quantum bits can have states Large-scale quantum computing
68. Some Quantum Algorithms • Using the quantum properties as they are: Superpolynomial speedup ◦ Quantum simulation -> drug design, materials development • Exploiting the structure of problems: Superpolynomial speedup ◦ Factoring, discrete-log problems, semidefinite programming, pattern matching, PCA, etc. • Generally using interference: Polynomial speedup ◦ Finding inverse functions, etc. • http://math.nist.gov/quantum/zoo/ • https://www.qmedia.jp/tag/quantum-algorithm/
69. Summary • What is quantum computing? • Quantum key distribution networks with trusted nodes ◦ Quantum networks for classical computers • The true quantum internet through quantum relays ◦ Quantum networks for quantum computers PR: R4D has an exhibition booth! Please check it out!