13-19 June 2015
University of Alberta
America/Edmonton timezone
Welcome to the 2015 CAP Congress! / Bienvenue au congrès de l'ACP 2015!

Towards a Quantum Non-Demolition Measurement for Photonic Qubits

16 Jun 2015, 16:30
CCIS L2-200 (University of Alberta)

CCIS L2-200

University of Alberta

Oral (Student, In Competition) / Orale (Étudiant(e), inscrit à la compétition) Division of Atomic, Molecular and Optical Physics, Canada / Division de la physique atomique, moléculaire et photonique, Canada (DAMOPC-DPAMPC) T3-2 Quantum Computation and Communication (DTP-DCMMP-DAMOPC) / Communication et calcul quantique (DPT-DPMCM-DPAMPC)


Chetan Deshmukh (University of Calgary)


Many applications of quantum information processing benefit from, or even require, the possibility to detect the number of photons in a given signal pulse without destroying the photons nor the encoded quantum state. We propose and show first steps towards the implementation of such a Quantum Non-Demolition (QND) measurement for time-bin qubits. To implement this measurement, we first store a ‘probe’ pulse in a cryogenically cooled Tm:LiNbO3 waveguide using an Atomic Frequency Comb (AFC) quantum memory protocol [1]. We then send a ‘signal’ pulse comprised of two temporal modes off-resonantly with the AFC through a previously prepared transparency window. The off-resonant interaction between the propagating signal and the thulium ions, onto which the probe pulse was mapped, results in the atomic state acquiring a phase-shift. This phase shift is imprinted onto the recalled probe pulse and can be determined using an interferometric measurement. The magnitude of this phase-shift depends on the signal pulse's energy, and detuning w.r.t to the probe pulse. Hence, knowing the phase-shift, we can determine the intensity or the number of photons in the signal pulse. [1] E. Saglamyurek et al, … Nature 2011

Primary author

Chetan Deshmukh (University of Calgary)


Prof. Christoph Simon (Collaborating professor) Dr Daniel Oblak (Post-Doc) Dr Khabat Heshami (Post-doc) Mr Neil Sinclair (PhD student) Prof. Wolfgang Tittel (Advising professor)

Presentation Materials

There are no materials yet.
Your browser is out of date!

Update your browser to view this website correctly. Update my browser now