Resolving photon number using superconducting detectors

Project Duration: 6 weeks

Hours of Engagement: 36

Project Description:

The photon is a rich physical system that can carry information. Polarisation, frequency, path, and transverse modes are commonly used for quantum information because photons produced via spontaneous parametric downconversion (SPDC) are entangled in these properties. Generation of entangled photons often occurs in a low-gain regime in order to suppress multiphoton events that conventional single-photon detectors cannot detect. However, with the development of superconducting nanowire single photon detectors (SNSPD), it is now possible to resolve at least small photon numbers (1 to 5 photons). Photon number resolution like this allows the photon number to be also used as a basis for quantum information. In this project, we will characterise an SNSPD and collect the SNSPD output for varying photon mean numbers. We will then use either statistics or machine learning techniques to identify different characteristic signatures for different photon numbers.

Expected Outcomes:

Basic knowledge of aligning an optical system; using an oscilloscope; digital signal processing; statistical analysis.

Suitable for:

Background in digital signal processing will be good (not necessary).

Contact for further information:

Associate Professor Jacquiline Romero: m.romero@uq.edu.au