Conveners
W3-1 Quantum Information: Theory (DAMOPC) / Information quantique: théorie (DPAMPC)
- Jens Lassen (TRIUMF)
By exploiting effects such as quantum superpositions and entanglement, quantum computers could solve problems that are intractable on standard, classical, computers. While building a full-scale quantum computer capable of rivalling with today’s supercomputers remains a challenge, the last few years have seen tremendous improvements in our ability to build small superconducting quantum...
To utilize the advantages of different quantum platforms, we need an interface (transducer) to transfer quantum information from one to another. Unfortunately, realistic transducers are imperfect due to, e.g. weak interaction strength or unwanted coupling. In this talk, I will present a surprising strategy to remedy the transduction imperfections: by applying a bad transducer twice [1]. I...
Information engines are the modern realization of the Maxwell demon, a thought experiment that revealed that information is also a thermodynamic quantity. We build and study a simple information-to-work engine, which consists of a heavy bead, in a water bath, trapped by optical tweezers. The bead undergoes Brownian motion due to the thermal fluctuations in the bath. The position of the bead is...
We investigate in the present work the doubly excited states (DES) in the Helium-like O6+ and F7+ ions. The interaction of these systems with X-ray laser pulses can cause the DES to appear in their energy spectra due to the strong correlation between the electrons. The formation of the DES can be followed by a decay by electron emission (autoionization) causing the parent ion to lose its...
The simulation of quantum systems is inherently difficult due to the exponentially scaling of the state that must be simulated for a general system. One clear way to get around this problem is to utilize the properties of the quantum physics it’s self, ergo simulate quantum physics on quantum physics. An exciting frontier in quantum information science is the realization and control of complex...
Trapped-ion quantum states are well-known to be good candidates for qubits in quantum computing. I will study the application of an adiabatic method known as STIRAP to achieve qubit switching. Stimulated Raman Adiabatic Passage (STIRAP) is a method of quantum control that utilizes a specific atomic structure known as a 3-Level Lambda System (3LLS). The system consists of two ground states that...
The nonclassicality of simple spin systems as measured by Wigner negativity is studied on a spherical phase space. Several SU(2)-covariant states with common qubit representations are addressed: spin coherent, spin cat (GHZ/N00N), and Dicke (W). We derive an upper bound on the Wigner negativity of spin cat states that rapidly approaches the true value as spin increases beyond $j \approx 5$. ...
We seek to design experimentally feasible broadband multiplexed optical quantum memory with near-term applications to telecom bands. Specifically, we devise dispersion compensation for an impedance-matched narrow-band quantum memory by exploiting Raman processes over two three-level atomic subensembles, one for memory and the other for dispersion compensation. Our proposed...
