arXiv subjects

Özgür E. Müstecaplioğlu

Publications and source records attributed to Özgür E. Müstecaplioğlu.

3 recordsLinked to original sources

arXiv2020

Quantum Thermodynamics and Quantum Coherence Engines

Advantages of quantum effects in several technologies, such as computation and communication, have already been well appreciated, and some devices, such as quantum computers and communication links, exhibiting superiority to their classical counterparts have been demonstrated. The close relationship between information and energy motivates us to explore if similar quantum benefits can be found in energy technologies. Investigation of performance limits for a broader class of information-energy machines is the subject of the rapidly emerging field of quantum thermodynamics. Extension of classical thermodynamical laws to the quantum realm is far from trivial. This short review presents some of the recent efforts in this fundamental direction and focuses on quantum heat engines and their efficiency bounds when harnessing energy from non-thermal resources, specifically those containing quantum coherence and correlations.

quant-ph↗

arXiv2013

Optical bistability in one dimensional doped photonic crystals with spontaneously generated coherence

We investigate optical bistability in a multilayer one-dimensional photonic crystal where the central layer is doped with $Λ$-type three level atoms. We take into account the influence of spontaneously generated coherence when the lower atomic levels are sufficiently close to each other, in which case Kerr-type nonlinear response of the atoms is enhanced. We calculate the propagation of a probe beam in the defect mode window using numerical nonlinear transfer matrix method. We find that Rabi frequency of a control field acting on the defect layer and the detuning of the probe field from the atomic resonance can be used to control the size and contrast of the hysteresis loop and the threshold of the optical bistability. In particular we find that, at the optimal spontaneously generated coherence, three orders of magnitude lower threshold can be achieved relative to the case without the coherence.

quant-ph↗

arXiv2012

Two-Frequency Jahn-Teller Systems in Circuit QED

We investigate the simulation of Jahn-Teller models with two non-degenerate vibrational modes using a circuit QED architecture. Typical Jahn-Teller systems are anisotropic and require at least a two-frequency description. The proposed simulator consists of two superconducting lumped-element resonators interacting with a common flux qubit in the ultrastrong coupling regime. We translate the circuit QED model of the system to a two-frequency Jahn-Teller Hamiltonian and calculate its energy eigenvalues and the emission spectrum of the cavities. It is shown that the system can be systematically tuned to an effective single mode Hamiltonian from the two-mode model by varying the coupling strength between the resonators. The flexibility in manipulating the parameters of the circuit QED simulator permits isolating the effective single frequency and pure two-frequency effects in the spectral response of Jahn-Teller systems.

quant-ph↗