Observation of a Quantum Phase from Classical Rotation of a Single Spin

Abstract

The theory of angular momentum connects physical rotations and quantum spins together at a fundamental level. Physical rotation of a quantum system will therefore affect fundamental quantum operations, such as spin rotations in projective Hilbert space, but these effects are subtle and experimentally challenging to observe due to the fragility of quantum coherence. Here we report a measurement of a single-electron-spin phase shift arising directly from physical rotation, without transduction through magnetic fields or ancillary spins. This phase shift is observed by measuring the phase difference between a microwave driving field and a rotating two-level electron spin system, and can accumulate nonlinearly in time. We detect the nonlinear phase using spin-echo interferometry of a single nitrogen-vacancy qubit in a diamond rotating at 200,000 rpm. Our measurements demonstrate the fundamental connections between spin, physical rotation and quantum phase, and will be applicable in schemes where the rotational degree of freedom of a quantum system is not fixed, such as spin-based rotation sensors and trapped nanoparticles containing spins.

Interplay between geometric and dynamic phases in a single-spin system

“…Additional avenues of future investigation could focus on the effects of physical rotation on spin manipulations, recently reported in Ref. [37]. In that particular case, physical rotation of the NV qubit leads to nonlinear accumulation of a relative phase between the NV and microwave field, which is detected in a spin-echo experiment.…”

“…Our experimental setup is designed to rotate diamonds containing single NV centers [36,37] and consists of a 12 Cenriched CVD diamond mounted on its (100) face. The motor that ordinarily rotates the diamond is held constant at a static rotation angle and not altered during any experiments.…”

Detectable Signature of Quantum Friction on a Sliding Particle in Vacuum

“…[ 42 ] As the existing bibliography reflects, GPs have become a fruitful venue of investigation to infer features of a quantum system due to their topological properties and close connection with gauge theories of quantum fields. Under suitable conditions, the corrections induced by the presence of the environment can be measured by means of an interferometric experiment (atomic interference) [ 50–53 ] or by NMR techniques. [ 54 ] In the case of open quantum evolution, the geometric phase that the system acquires differs from that acquired when the evolution is closed [ 43 ] since it is now affected by non‐unitary effects such as decoherence and dissipation.…”

Initiating revolutions for optical manipulation: the origins and applications of rotational dynamics of trapped particles

“…Another possibility to observe superposition states without low translational temperatures is presented by experiments with nitrogen-vacancy (NV) centres in nanodiamond. In analogy with trapped atomic ions, which have a rich history of use as spin-mechanical systems where the internal state of the atoms is coupled to their external motion [244], the state of the electron spin of the NV-centre can be coupled to (and therefore interrogated by) the classical rotation [310]. This can even be used to control and cool the classical motion of the nanodiamond [241].…”