Heavy metals are a major public health concern and their on-site detection in water supplies is not well served by existing lab techniques. We develop a new multi-modal platform comprising functionalized quantum dots of two-dimensional materials (2D-QDs) for the sensing of four highly-toxic heavy metal pollutants (arsenic, cadmium, lead and mercury). The zero-dimensional nature of quantum dots brings essential properties necessary for fluorescence-based chemical sensing of heavy metals in the field. We focus on one type of 2D material, molybdenum disulfide (MoS2), which is a direct band gap semiconductor when produced as a monolayer. To fabricate and functionalize the 2D-QDs, we expose flakes of MoS2 suspended in a solution to a pulsed laser. This technique allows us to simultaneously functionalize the 2D-QDs, so that they become sensitive to a specific pollutant metal, and control their fluorescence wavelength, so that 2D-QDs functionalized for different target metals will produce distinguishable optical signals. By combining multiple types of functionalized 2D-QDs into a single solution capable of simultaneously identifying various heavy metals, we expect to advance a range of applications that require a field-deployable solution. These include for example, rapid contaminant point source identification, and water analysis of heavy metals in developing countries where conventional equipment is too costly.
Qubits and Quantum Effects in Biology
It is unknown whether biological processes make direct use of quantum effects, as opposed to depending merely on the influence of quantum physics on chemical bonding and molecular structure.
June 1, 2017
Entangled Photon Orbital Angular Momentum Arrays
Summary Arrays of orbital angular momentum (OAM) states of light are a new form of structured light so far relatively unexplored in quantum information science. Unlike spin angular momentum of light, which is related to light’s polarization and covers two dimensions, OAM states, sometimes described as ‘donut beams’ due to the shape of the field […]
September 19, 2019
Implementing High-fidelity Quantum Gates in Multi-level Trapped Ions
Summary The scalability of quantum processors is limited by current error rates for single-qubit gates. By encoding more than a single bit of information within a single ion, multi-level “qudits” offer a promising method of increasing the information density within a quantum processor, and therefore minimizing the number of gates and associated error rates. […]
July 30, 2018
Quantum Dynamics of Cavity Interactions with Spin Ensembles
Summary High quality factor cavities can be powerful control elements for ensembles of spins, enabling unitary control as well as on demand cooling. They can also be used to couple two otherwise non-interacting ensembles. The goal of the project is to explore the physics and engineering of such systems both theoretically and experimentally. The laboratory contains a […]
September 7, 2016