6 research outputs found
Exploring quantum chaos with a single nuclear spin
Most classical dynamical systems are chaotic. The trajectories of two identical systems prepared in infinitesimally different initial conditions diverge exponentially with time. Quantum systems, instead, exhibit quasiperiodicity due to their discrete spectrum. Nonetheless, the dynamics of quantum systems whose classical counterparts are chaotic are expected to show some features that resemble chaotic motion. Among the many controversial aspects of the quantum-classical boundary, the emergence of chaos remains among the least experimentally verified. Time-resolved observations of quantum chaotic dynamics are particularly rare, and as yet unachieved in a single particle, where the subtle interplay between chaos and quantum measurement could be explored at its deepest levels. We present here a realistic proposal to construct a chaotic driven top from the nuclear spin of a single donor atom in silicon, in the presence of a nuclear quadrupole interaction. This system is exquisitely measurable and controllable, and possesses extremely long intrinsic quantum coherence times, allowing for the observation of subtle dynamical behavior over extended periods. We show that signatures of chaos are expected to arise for experimentally realizable parameters of the system, allowing the study of the relation between quantum decoherence and classical chaos, and the observation of dynamical tunneling
Coherent control of NV- centers in diamond in a quantum teaching lab
The room temperature compatibility of the negatively-charged nitrogen-vacancy
(NV-) in diamond makes it the ideal quantum system for a university teaching
lab. Here, we describe a low-cost experimental setup for coherent control
experiments on the electronic spin state of the NV- center. We implement
spin-relaxation measurements, optically-detected magnetic resonance, Rabi
oscillations, and dynamical decoupling sequences on an ensemble of NV- centers.
The relatively short times required to perform each of these experiments (<10
minutes) demonstrate the feasibility of the setup in a teaching lab. Learning
outcomes include basic understanding of quantum spin systems, magnetic
resonance, the rotating frame, Bloch spheres, and pulse sequence development.Comment: 16 pages, 9 figure
Observing hyperfine interactions of NV centers in diamond in an advanced quantum teaching lab
The negatively charged nitrogen-vacancy (NV) center in diamond is a model
quantum system for university teaching labs due to its room-temperature
compatibility and cost-effective operation. Based on the low-cost experimental
setup that we have developed and described for the coherent control of the
electronic spin (Sewani et al.), we introduce and explain here a number of more
advanced experiments that probe the electron-nuclear interaction between the
\nv electronic and the \NN~and \CC~nuclear spins. Optically-detected magnetic
resonance (ODMR), Rabi oscillations, Ramsey fringe experiments, and Hahn echo
sequences are implemented to demonstrate how the nuclear spins interact with
the electron spins. Most experiments only require 15 minutes of measurement
time and can, therefore, be completed within one teaching lab.Comment: Extension of the teaching lab experiments described in Sewani et al.,
Coherent control of NV centers in diamond in a quantum teaching lab. American
Journal of Physics 88, 1156 (2020). https://doi.org/10.1119/10.000190