This presentation was created for a first year physics project at Imperial. A presentation describing some of the applications of quantum entanglement, for example: quantum clocks, quantum computing, teleportation and quantum cryptography. Refers to specific experiment of teleportation carried out by NIST using time-bin encoding.

1. Applications of Quantum
Entanglement
Team Fx
A. Ball
S.T.J. O’Neill
P.G. O’Shea
P.M. Plesniak
T.A.O. Rashid

2. Quantum Entanglement
• For two entangled particles, a change in one effects
the other regardless of the distance between
• Suggests faster than light travel – ‘Spooky action at a
distance’
• Can happen naturally or in labs
• Cannot measure the quantum state of two particles –
measuring one destroys the entangled state
• Has many applications in physics

3. Timekeeping
• Standard clocks depend on location
• Quantum clocks are absolute
• Current definition of a second hard to maintain
• May entangle single atoms which oscillate in specific
modes, emitting specific frequency of energy
• Multiple entangled atoms per clock
• Clocks distributed on satellites, creating a better UTC

4. Fig.1: Diagram showing

5. Research at Imperial
• 2013 research project by Prof. Ed Hinds in the
Centre for Cold Matter on ultra-precise clocks and
sensors
• Involved crating a portable device for creating ultra-
cold atoms
• This is key for development of quantum clocks

6. Quantum Computing
• Calculations currently use binary operations
• Recent use of particles’ quantum states, with
calculations performed using Principle of
Superposition
• E.g. Spin
• Information stored as qubits
• Calculations based on end product of interference
• Quantum computers should be more efficient by
2030

7. Fig.2: Google’s D-Wave quantum
computer. Recently doubled processing to
1000 qubits, and can do calculations

8. “Teleportation, or the ability to transport a person or
object instantly from one place to another, is a
technology that could change the course of civilisation
and alter the destiny of nations”.
Physics of the Impossible, Michio Kaku

9. Quantum Teleportation
• Requires entangled pairs of particles
• To the observer a particle will simultaneously take
the others’ quantum state
• This is instantaneous
• It is termed ‘Quantum teleportation’
Fig.3: Diagram showing basic
principles of quantum teleportation

10. Experiments in Quantum Teleportation
1963 - IBM 2004 – University of Vienna
1997 – University of Innsbruck 2015 - NIST

11. The NIST Experiment
• Uses time-bin encoding, instead of polarisation of
photons, as the quantum information sent
• This is preserved better over large distances
• Encoded with Mach-Zender interferometer
Fig.4: Mach-Zender Interferometer

12. Experimental Results
• Four fold improvement over previous experiments
• Successful over 80% of the time
• Similar results to those over much shorter distances
• Could lead to quantum networks

13. Quantum Cryptography
• Particle transferred via entanglement to receiver
• System cannot be measured without being disturbed
• Receiver immediately notified
• E.g. BBN Technologies and Toshiba
• Only used over 88 miles so far

14. Fig.5: Diagram showing the basic
principles of quantum cryptography