PhD Candidate: Muhammet Yurtalan
Supervisors: Adrian Lupascu and Zbigniew Wasilewski
Thesis on display in the Engineering graduate office, E7-7402.
Oral defence in EIT 3142.
Recent progress in creating graphene quantum dots (QDs) with fixed build-in potentials has offered a new platform to visualize and probe the confined electronic states. In this talk, I describe scanning tunneling spectroscopy measurements of the energy spectrum of graphene QDs as a function of energy, spatial position, and magnetic field.
Microwave optomechanical circuits have been demonstrated in the past years to be powerful tools for both, exploring fundamental physics of macroscopic and massive quantum objects as well as being promising candidates for novel on-chip quantum limited microwave devices. In this work, we explore a microwave optomechanical device consisting of a coplanar microwave cavity coupled to a mechanical high quality factor nanobeam resonator.
Superconducting circuits have emerged as a competitive platform for quantum computation, satisfying the challenges of controllability, long coherence and strong interactions. Here we apply this toolbox to the exploration of strongly correlated quantum materials made of microwave photons. We develop a versatile recipe that uses engineered dissipation to stabilize many-body phases, protecting them against intrinsic photon losses.
Silicon (Si) CMOS spin qubits have become a promising platform for a future quantum information processor due to recent demonstrations of high fidelity single and two qubit gates [Veldhorst et. al., Nature 526.7573 (2015)], compatibility with industrial CMOS process and promising prospects for scalability.
Cooling atomic gases to quantum degeneracy opened the new field of quantum simulation. Here the precise tools of atomic physics can be used to study exotic models from condensed matter or nuclear physics with unique tunability and control. Ultracold molecules bring many new possibilities to quantum simulation. I will review the physics of ultracold molecules, including our recent production of stable, ultracold triplet molecules and what they can add to quantum simulation.
The development of atom-like quantum sensors in wide bandgap materials, for instance Nitrogen Vacancy (NV) centers in diamond, has thrown up exciting new possibilities for the sensing of materials, molecules and biological systems through optical means. In particular I will describe the development of “quantum-assisted” magnetic resonance probes based on the NV center that allows sensing of nano- and meso-scale volumes at high spatial and frequency resolution [1,2].
The time-frequency degree of freedom of light offers an intrinsically high-dimensional encoding space which is naturally compatible with waveguide devices and fiber infrastructure. However, coherent manipulation and measurement the information-carrying modes presents a challenge due to the sub-picosecond timescales inherent to downconversion-based photon sources. In this talk, I will discuss methods based on ultrafast pulse shaping and sum-frequency generation to address these temporal modes.
As a more general form of quantum superposition, quantum coherence represents one of the most fundamental features that set the difference of quantum mechanics from the classical realm. In this talk, we will use the tool of semidefinite programming to study two fundamental tasks relating quantum coherence, i.e., coherence distillation of quantum states and coherence cost of quantum processes.
Significant global efforts are currently underway to build quantum computers. The two main goals for near-term quantum computers are finding and solving interesting problems in the presence of noise and developing techniques to mitigate errors. In this talk, I will outline and motivate an abstraction layer needed to reliably operate quantum computers under realistic noise models, namely, a cycle consisting of all the primitive gates applied to a quantum computer within a specified time period.