The MacroPhoton demonstrator is a hands‑on, interactive, quantum physics experiment for all the family. In response to an open request from the Quantum City public engagement initiative, it was designed and built entirely at Heriot‑Watt University by Dr Robert Collins and co‑funded by the School of Engineering and Physical Sciences and the UK Quantum Technology Hub for Quantum Communications Technologies.

Specifically, it is a demonstrator of the Bennett‑Brassard 1984 quantum key distribution protocol (QKD). This protocol is the basis of much of quantum communications and provides a foundation for students. The demonstrator was originally designed to be most effective for students who have previously achieved SCQF Level 5 in Physics. However, methods for dynamically pitching the ideas to all ages and abilities have been developed.

A typical visitor is introduced to the concept of polarisation of light and encouraged to play with both toy example and real optical linear polarisers and is encouraged to predict the outcome of the Dirac three polarisers experiment (DTPE). Anecdotally, this has proven to be an effective way to pique the interest of visitors, and also serves to introduce them to the scientific method (theorizing then experimenting). The explanation of the DTPE (quantum superposition and wave function collapse) is no longer an abstract concept, but an explanation of something they have seen for themselves.

From here, the MacroPhoton lets two volunteers use these concepts to generate a random bit string (their "secret key") in two places at once, without ever communicating the key itself. We then talk them through using their newly generated key to share a message using a cryptographic shift cipher.

Hop in for the ride...

Click here to see some pictures

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Public engagement events attended

The UK Quantum Communications Hub are engaging into a partnership with the National STEM Learning Centre and the University of York Science Education Group to deliver a comprehensive scheme of quantum‑related CPD and classroom‑based activities for A‑level students and their science teachers, with the specific aim of promoting the uptake of STEM subjects, highlighting the benefits and applications of mature quantum technologies and signposting career pathways for science graduates.

The scheme is seeking to increase awareness and understanding of the importance and relevance of quantum technologies to UK society, culture and the economy. Over a 2‑year period, the project partners working closely with the other UK technology hubs will use the science and technologies of the national quantum technologies programme as a context in which to develop and deliver an inspiring enrichment scheme across the UK.

The scheme is UK wide – achieved by a collaborative approach involving a wide network of partners and support organisations.

For more information click here.


Quantum City is a joint public engagement initiative by many stakeholders of the UK National Quantum Technologies Programme. It brings together researchers from the UK Quantum Technology Hubs, Centres for Doctoral Training and National Physical Laboratory.

Through a joint communications and impact evaluation plan, a series of science festival demonstrations, strong online presence and a coordinated social media strategy, participating partners hope to instil an understanding of the benefits of quantum technologies, showcase the UK’s expertise in this area, and inspire young audiences to become the next generation of quantum technologists.

For more information click here.