Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userEnhancement of the optomechanical coupling and Kerr nonlinearity using the Josephson Capacitance of Cooper-pair box
127
0
0.0
(
0
)
Authors
Mohammad Tasnimul Haque
Ask ChatGPT about the research
No Arabic abstract
We propose a scheme for enhancing the optomechanical coupling between microwave and mechanical resonators by up to seven orders of magnitude to the ultrastrong coupling limit in a circuit optomechanical setting. The tripartite system considered here consists of a Josephson junction Cooper-pair box that mediates the coupling between the microwave cavity and the mechanical resonator. The optomechanical coupling can be modified by tuning the gate charge and the magnetic flux bias of the Cooper-pair box which in turn affect the Josephson capacitance of the Cooper-pair box. We additionally show that with suitable choice of tuning parameters, the optomechanical coupling vanishes and the system exhibits purely a cross-Kerr type of nonlinearity between the cavity and the mechanical resonator. This allows the system to be used for phonon counting.
rate research
Read More
Few-photon optomechanical effects are not only important physical evidences for understanding the radiation-pressure interaction between photons and mechanical oscillation, but also have wide potential applications in modern quantum technology. Here we study the few-photon optomechanical effects including photon blockade and generation of the Schr{o}dinger cat states under the assistance of a cross-Kerr interaction, which is an inherent interaction accompanied the optomechanical coupling in a generalized optomechanical system. By exactly diagonalizing the generalized optomechanical Hamiltonian and calculating its unitary evolution operator, we find the physical mechanism of the enhancement of photon blockade and single-photon mechanical displacement. The quantum properties in this generalized optomechanical system are studied by investigating the second-order correlation function of the cavity field and calculating the Wigner function and the probability distribution of the rotated quadrature operator for the mechanical mode. We also study the influence of the dissipations on the few-photon optomechanical effects.
Here we present an architecture for the implementation of cyclic quantum thermal engines using a superconducting circuit. The quantum engine consists of a gated Cooper-pair box, capacitively coupled to two superconducting coplanar waveguide resonators with different frequencies, acting as thermal baths. We experimentally demonstrate the strong coupling of a charge qubit to two superconducting resonators, with the ability to perform voltage driving of the qubit at GHz frequencies. By terminating the resonators of the measured structure with normal-metal resistors whose temperature can be controlled and monitored, a quantum heat engine or refrigerator could be realized. Furthermore, we numerically evaluate the performance of our setup acting as a quantum Otto-refrigerator in the presence of realistic environmental decoherence.
This Comment has been withdrawn according to a mutual agreement between the authors of the original paper and the authors of this Comment.
The advent of quantum optical techniques based on superconducting circuits has opened new regimes in the study of the non-linear interaction of light with matter. Of particular interest has been the creation of non-classical states of light, which are essential for continuous-variable quantum information processing, and could enable quantum-enhanced measurement sensitivity. Here we demonstrate a device consisting of a superconducting artificial atom, the Cooper pair transistor, embedded in a superconducting microwave cavity that may offer a path toward simple, continual production of non-classical photons. By applying a dc voltage to the atom, we use the ac Josephson effect to inject photons into the cavity. The backaction of the photons on single-Cooper-pair tunneling events results in a new regime of simultaneous quantum coherent transport of Cooper pairs and microwave photons. This single-pair Josephson laser offers great potential for the production of amplitude-squeezed photon states and a rich environment for the study of the quantum dynamics of nonlinear systems.
This paper is devoted to an analysis of the experiment by Nakamura {it et al.} (Nature {bf 398}, 786 (1999)) on the quantum state control in Josephson junctions devices. By considering the relevant processes involved in the detection of the charge state of the box and a realistic description of the gate pulse we are able to analyze some aspects of the experiment (like the amplitude of the measurement current) in a quantitative way.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
