Explore quantum sensing, communication and entanglement this spring term at IQC.
Dive into advanced topics through a flexible series of three modules. Attend individual sessions based on your interests, or complete all three for 0.25 course credit by enrolling in QIC891 - Topics in Quantum Information. As an alternative, you can enrol in QIC890-003 - Topics in Quantum Information to receive a 0.5 course credit. Enrolment in this section will include taking the Quantum Key Distribution Summer School 2025 in addition to the three modules.
All IQC members (students, postdoctoral fellows and faculty) are welcome to attend Modules 1 and 2 without registering—consider these as tutorial sessions open to all. Module 3 (Bell’s inequality workshop) includes a lab component and has limited capacity, but we still expect space will be available for students not taking the course for credit.
Module 1: Quantum sensing
Instructor: Bradley Hauer
Dates: July 3, 8, 10, 15
Time: 3 to 4:30 p.m.
Location: QNC 1201
This module introduces the fundamental concepts of quantum sensing and is intended primarily for graduate students in engineering, physics, or related fields with an interest in engineered quantum systems. We will use the framework of quantum mechanics to explore the limits quantum mechanics imposes on sensors, as well as how quantum phenomena can be used to surpass classical sensing techniques.
Topics will include the standard quantum limit, Heisenberg uncertainty principle, Fisher information, quantum Cramer-Rao bound, autocorrelation functions, spectral densities, fluctuation-dissipation theorem, quantum noise, decoherence, quantum measurement, backaction, detection inefficiencies and amplification.
Time permitting, we will apply these concepts to study the non-classical behaviour of the two commonly used quantum sensing platforms of cavity optomechanics and superconducting circuits.
Module 2: Implementation of quantum communication
Instructor: Thomas Jennewein
Dates: July 17, 21, 22, 24
Time: 10 to 11:30 a.m.
Location: QNC 1201
We will discuss the main approaches and technologies used in photonic quantum communication systems, and particular emphasis is given on realistic device and system properties.
Topics will include:
- An Introduction to Quantum Communication Protocols, such as quantum key distribution, quantum teleportation & entanglement swapping, sources for Single Photons, sources for entangled photons including ideal photon sources, quantum dots, SPDC, atomic vapor, atoms/ions and linear optical approaches.
- Single-photon detectors for the relevant wavelength ranges, quantum channels for photons including optical fibre and free-space, and their behavior for the different encoding of photonic quantum information.
- Quantum communication implementations including quantum key distribution in optical fibers/free space/satellites, quantum teleportation and entanglement swapping, quantum repeaters, dense coding, quantum coin-tossing and bit-commitment, reference free quantum communication.
Module 3: Entanglement and Bell’s Inequality — A hands-on workshop
Instructor: Michael Grabowecky
Dates: July 29, 31 | Time: 10 to 11:30 a.m.
Dates: August 5, 7 | Time: 3:30 to 6:30 p.m.
Location: RAC
Entanglement is a central concept in quantum mechanics and plays a role in many quantum technologies. It is a consequence of the superposition principle applied to multi-party quantum states and gives rise to correlations in their joint measurement results that cannot be explained with a classical theory. It is an important resource for quantum computing, quantum communications, and quantum sensing. Entanglement was recognized early on in the development of quantum mechanics as something revolutionary.
In the work by Einstein Podolsky Rosen from 1935 it was exploited to show that quantum mechanics could not be a complete theory, a claim that was famously challenged by Neils Bohr. At the same time, Schrödinger called it “...the characteristic trait of quantum mechanics, the one that enforces its entire departure from classical lines of thought.”
In this hands-on module, we will combine lecture and experiment to explore how quantum entanglement is prepared in the lab. We will use parametric downconversion to generate polarization entangled single photons. The resulting quantum correlations of the two-party entangled state will be characterized and used to test the Clauser-Horne-Shimony-Holt (CHSH) Bell inequality, which historically was the first experimental demonstration that quantum mechanics does not satisfy local realism.