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EP-4736350-A2 - QUANTUM ENTANGLEMENT DISTRIBUTION USING MULTIPLE OPTICAL PATHS AND AUTOMATED SWITCHOVER

EP4736350A2EP 4736350 A2EP4736350 A2EP 4736350A2EP-4736350-A2

Abstract

A system and method for distributing quantum entanglement using optically protected fiber optical paths is described. In some embodiments, multiple optical paths are used to connect a source site to a receiver site. Quantum entangled particles are transmitted from the source site to the receiver site using a first one of the multiple optical paths and related service channel information is transmitted from the source site to the receiver site using a second one of the multiple optical paths. In response to a failure of either the first or second optical path, an entanglement distribution controller automatically updates the routing such that the service channel information and the quantum entangled particles are routed concurrently on a remaining one of the first or second optical path.

Inventors

  • BERNARDI, GIACOMO

Assignees

  • Amazon Technologies, Inc.

Dates

Publication Date
20260506
Application Date
20240618

Claims (15)

  1. 1. A quantum entanglement distribution system, comprising: one or more switches coupled to a plurality of optical paths; and one or more power detectors configured to detect signal power for light transmitted using one or more of the plurality of optical paths; and one or more computing devices configured to: cause quantum entangled particles to be transmitted from a source site to a receiver site via a first one of the plurality of optical paths; concurrently cause service channel information to be transmitted from the source site to the receiver site via a second one of the plurality of optical paths; and in response to a signal power measurement for the service channel information falling below a threshold level: cause the one or more switches to route the service channel information from the source site to the receiver site via the first optical path; and provide an indication that the second optical path is currently unavailable as a spare optical path for transmission of the quantum entangled particles from the source site to the receiver site.
  2. 2. The quantum entanglement distribution system of claim 1, wherein the quantum entangled particles and the service channel information are transmitted using different frequencies of light.
  3. 3. The quantum entanglement distribution system of claim 2, wherein: a first portion of the service channel information is transmitted from the source site to the receiver site using a first wavelength of light, a second portion of the service channel information is transmitted from the receiver site to the source site using a second wavelength of light, and the quantum entangled particles are transmitted from the source site to the receiver site using a third wavelength of light.
  4. 4. The quantum entanglement distribution system of any of claims 1 through 3, wherein the entangled quantum particles comprise secure shared randomness used for quantum encrypted key distribution.
  5. 5. The quantum entanglement distribution system of claim 1, wherein the source site and the receiver site comprise respective data centers of a service provider network.
  6. 6. The quantum entanglement distribution system of claim 1, wherein the source site comprises a data center of a service provider network, and the receiver site comprises computing resources of a customer of the service provider network.
  7. 7. The quantum entanglement distribution system of any of claims 1 through 6, wherein the one or more computing devices are further configured to: receive information indicating a failure, at the receiver site, to receive the quantum entangled particles; cause, at the source site, a given one of the one or more switches to switch such that a quantum entanglement source at the source site is aligned to transmit the quantum entangled particles using the second optical path.
  8. 8. The quantum entanglement distribution system of any of claims 1 through 6, wherein providing the indication that the second optical path is currently unavailable as a spare optical path for transmission of the quantum entangled particles from the source site to the receiver site comprises: sending, prior to switching the routing of the service channel information to be over the first optical path, a message in the service channel information transmitted over the second optical path, wherein the message indicates to switch the service channel information routing to the first optical path.
  9. 9. The quantum entanglement distribution system of any of claims 1 through 6, wherein providing the indication that the second optical path is currently unavailable as a spare optical path for transmission of the quantum entangled particles from the source site to the receiver site comprises: interrupting for a set amount of time, prior to switching the routing of the service channel information to be over the first optical path, transmission of the service channel information transmitted over the second optical path, wherein the interruption for the set amount of time indicates to switch the service channel information routing to the first optical path.
  10. 10. The quantum entanglement distribution system of claim 1, wherein the one or more computing devices are further configured to: detect a restoration of the signal power measurement for the second optical path to a level above the threshold level; and in response to said detecting, cause the one or more switches to route the service channel information from the source site to the receiver site via the second optical path.
  11. 11. The quantum entanglement distribution system of claim 1, further comprising: the plurality of optical paths connecting the source site and the receiver site, wherein the plurality of optical paths are independent paths that do not have a shared geography.
  12. 12. The quantum entanglement distribution system of claim 11, wherein the service channel information further comprises: measurement basis information for measurements of the quantum entangled particles performed at the source site or the receiver site.
  13. 13. A method of distributing quantum entanglement, comprising: causing quantum entangled particles to be transmitted from a source site to a receiver site via a first optical paths concurrently causing service channel information to be transmitted from the source site to the receiver site via a second optical path; and in response to a signal power measurement for the service channel information falling below a threshold level: causing one or more switches to route the service channel information from the source site to the receiver site via the first optical path; and providing an indication that the second optical path is currently unavailable as a spare optical path for transmission of the quantum entangled particles from the source site to the receiver site.
  14. 14. The method of claim 13, further comprising: detecting a restoration of the signal power measurement for the second optical path to a level above the threshold level; and in response to said detecting, causing the one or more switches to route the service channel information from the source site to the receiver site via the second optical path.
  15. 15. The method of claim 13 or claim 14, wherein the quantum entangled particles and the service channel information are transmitted using different wavelengths.

Description

QUANTUM ENTANGLEMENT DISTRIBUTION USING MULTIPLE OPTICAL PATHS AND AUTOMATED SWITCHOVER BACKGROUND [0001] Quantum computing utilizes the laws of quantum physics to process information. Quantum physics is a theory that describes the behavior of reality at the fundamental level. It is currently the only physical theory that is capable of consistently predicting the behavior of microscopic quantum objects (e.g., particles) like photons, molecules, atoms, and electrons. [0002] A quantum computing device is a device that utilizes quantum mechanics to allow one to write, store, process and read out information encoded in quantum states, e.g., the states of quantum objects. A quantum object is a physical object that behaves according to the laws of quantum physics. The state of a physical object is a description of the object at a given time. [0003] In quantum mechanics, the state of a two-level quantum system, or simply, a qubit, is a list of two complex numbers, where the absolute sum of the complex numbers must sum to one. Each of the two numbers is called an amplitude, or quasi-probability. The square of an amplitude gives a potentially negative probability. Hence, each of the two numbers correspond to the square root that event zero and event one will happen, respectively. A fundamental and counterintuitive difference between a probabilistic bit (e.g., a traditional zero or one bit) and the qubit is that a probabilistic bit represents a lack of information about a two-level classical system, while a qubit contains maximal information about a two-level quantum system. [0004] Quantum computing devices are based on such quantum bits (qubits), which may experience the phenomena of “superposition” and “entanglement.” Superposition allows a quantum system to be in multiple states at the same time. For example, whereas a classical computer is based on bits that are either zero or one, a qubit may be both zero and one at the same time, with different probabilities assigned to zero and one. Entanglement is a strong correlation between quantum particles, such that the quantum particles are inextricably linked in unison even if separated by great distances. [0005] Public networks often rely on public key distribution mechanisms that have a security foundation based on the assumption that certain mathematical problems, e.g., integer factoring, cannot be solved efficiently. If these assumptions do not hold, such security is critically weakened. The advancement of quantum computers that can efficiently solve the factoring problem is an example of a cryptographic threat to such communications. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 illustrates a service provider network comprising data centers located at a source site and a receiver site, wherein dual fiber optic paths with optical line protection are used to distribute quantum entanglement from the data center at the source site to the data center at the receiver site, according to some embodiments. [0007] FIG. 2A illustrates a normal state configuration of a source site of a quantum entanglement distribution system, wherein dual fiber optic paths with optical line protection are used to distribute quantum entanglement from the source site to a receiver site, according to some embodiments. [0008] FIG. 2B illustrates a first one of the dual fiber optic paths with optical line protection in a failure state and a resulting configuration at the source site of the quantum entanglement distribution system, wherein an entanglement distribution controller automatically re-routes the quantum entanglement to be distributed along with service channel information using a second one of the dual fiber optic paths with optical line protection, according to some embodiments. [0009] FIG. 2C illustrates a second one of the dual fiber optic paths with optical line protection in a failure state and a resulting configuration at the source site of the quantum entanglement distribution system, wherein an entanglement distribution controller automatically re-routes the service channel information to be distributed along with the quantum entanglement distribution using the first one of the dual fiber optic paths with optical line protection, according to some embodiments. [0010] FIG. 3A illustrates a normal state configuration of a receiver site of a quantum entanglement distribution system, wherein dual fiber optic paths with optical line protection are used to distribute quantum entanglement from a source site to the receiver site, according to some embodiments. [0011] FIG. 3B illustrates a first one of the dual fiber optic paths with optical line protection in a failure state and a resulting configuration at the receiver site of the quantum entanglement distribution system, wherein an entanglement distribution controller automatically re-routes the quantum entanglement to be distributed along with service channel information using a second one of the dual fiber optic paths with opti