Nanomechanical squeezing: Toward quantum imaging with atomic force microscopy

Florent Lecocq, J. B. Clark, Raymond W. Simmonds +2 more

Ali Passian, George Siopsis

New classical modalities of atomic force microscopy continue to emerge to achieve higher spatial, spectral, and temporal resolution for nanometrology of materials. Here, we introduce the concept of a quantum-mechanical modality that capitalizes on squeezed states of probe displacement. We show that such squeezing is enabled nanomechanically when the probe enters the van der Waals regime of interaction with a sample. The effect is studied in the noncontact mode, where we consider the parameter domains characterizing the attractive regime of the probe-sample interaction force.

Alex Terrasson

Michael A. Taylor, Jiří Janoušek, Vincent R. Daria +4 more

Quantum effects may help devise new imaging schemes that can overcome classical constraints posed by noise and diffraction. By using squeezed states of light in photonic force microscopy (PFM), scientists have demonstrated a 14% quantum enhancement of PFM's spatial resolution, imaging details of living yeast cells with a resolution of 10 nm.

Aziz Kolkıran, G. S. Agarwal

We study the quantum properties of a nanomechanical oscillator via the squeezing of the oscillator amplitude. The static longitudinal compressive force $F_0$ close to a critical value at the Euler buckling instability leads to an anharmonic term in the Hamiltonian and thus the squeezing properties of the nanomechanical oscillator are to be obtained from the Hamiltonian of the form $H= a^†a+β(a^†+a)^4/4$. This Hamiltonian has no exact solution unlike the other known models of nonlinear interactions of the forms $a^{†2}a^2$, $(a^†a)^2$ and $a^{\dag4}+a^4-(a^{\dag2}a^2+a^2a^{\dag2})$ previously employed in quantum optics to study squeezing. Here we solve the Schrödinger equation numerically and show that in-phase quadrature gets squeezed for both ground state and coherent states. The squeezing can be controlled by bringing $F_0$ close to or far from the critical value $F_c$. We further study the effect of the transverse driving force on the squeezing in nanomechanical oscillator.

Morgan J. Choi, Christian J. Pluchar, Wenhua He +2 more