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Nahid Yazdi

Publications and source records attributed to Nahid Yazdi.

4 recordsLinked to original sources

Spin-induced multipartite steady-state entanglement of motional modes in hexagonal boron nitride membranes

In this paper, we focus on a scheme in which three high-quality-factor mechanical modes of a hexagonal boron nitride (hBN) membrane monolayer are coupled to a common optically addressable spin defect present in the membrane via magnetic field interaction. We show that this coupling induces an effective phonon-phonon interaction in the dispersive regime and under appropriate magnetic field and microwave modulation. We derive the Langevin-Heisenberg equations of motion for vibrational modes to analyze optimal parameter regimes for reaching a physically stable system. We also investigate the effect of coupling strength on purity and entanglement. Our results demonstrate that bipartite and genuinely tripartite steady-state entanglement between different vibrational modes of hBN may be achieved in a broad spectrum of experimental parameters. This study has the potential to enable scalability to be implemented for the generation of two-dimensional continuous-variable cluster states for universal quantum computation.

quant-ph

Multimode Gaussian steady state engineering in optomechanical systems with a squeezed reservoir

We investigate a theoretical protocol for the dissipative stabilization of mechanical quantum states in a multimode optomechanical system composed of multiple optical and mechanical modes. The scheme employs a single squeezed reservoir that drives one of the optical modes, while the remaining optical modes mediate an effective phonon-phonon interaction Hamiltonian. The interplay between these coherent interactions and the dissipation provided by the squeezed bath enables the steady-state preparation of targeted quantum states of the mechanical modes. In the absence of significant uncontrolled noise sources, the resulting dynamics closely approximate the model introduced in [Phys. Rev. Lett. 126, 020402 (2021)]. We analyze the performance of this protocol in generating mechanical cluster states defined on rectangular graphs.

quant-ph

Cooling microwave fields into general multimode Gaussian states

We show that a collection of lossy multi-chromatically modulated qubits can be used to dissipatively engineer arbitrary Gaussian states of a set of bosonic modes. Our ideas are especially suited to superconducting-circuit architectures, where all the required ingredients are experimentally available. The generation of such multimode Gaussian states is necessary for many applications, most notably measurement-based quantum computation. We build upon some of our previous proposals, where we showed how to generate single-mode and two-mode squeezed states through cooling and lasing. Special care must be taken when extending these ideas to many bosonic modes, and we discuss here how to overcome all the limitations and hurdles that naturally appear. We illustrate our ideas with a fully worked out example consisting of GHZ states, but have also tested several other examples such as cluster states. All these examples allow us to show that it is possible to use a set of N lossy qubits to cool down a bosonic chain of N modes to any desired Gaussian state.

quant-ph