Generation of Fock states in a superconducting quantum circuit
- 1 July 2008
- journal article
- Published by Springer Science and Business Media LLC in Nature
- Vol. 454 (7202), 310-314
- https://doi.org/10.1038/nature07136
Abstract
Spin systems and harmonic oscillators comprise two archetypes in quantum mechanics. The spin-1/2 system, with two quantum energy levels, is essentially the most nonlinear system found in nature, whereas the harmonic oscillator represents the most linear, with an infinite number of evenly spaced quantum levels. A significant difference between these systems is that a two-level spin can be prepared in an arbitrary quantum state using classical excitations, whereas classical excitations applied to an oscillator generate a coherent state, nearly indistinguishable from a classical state. Quantum behaviour in an oscillator is most obvious in Fock states, which are states with specific numbers of energy quanta, but such states are hard to create. Here we demonstrate the controlled generation of multi-photon Fock states in a solid-state system. We use a superconducting phase qubit, which is a close approximation to a two-level spin system, coupled to a microwave resonator, which acts as a harmonic oscillator, to prepare and analyse pure Fock states with up to six photons. We contrast the Fock states with coherent states generated using classical pulses applied directly to the resonator.Keywords
This publication has 27 references indexed in Scilit:
- Progressive field-state collapse and quantum non-demolition photon countingNature, 2007
- Exploring the QuantumPublished by Oxford University Press (OUP) ,2006
- Vacuum Rabi Oscillations in a Macroscopic Superconducting QubitOscillator SystemPhysical Review Letters, 2006
- Generation of photon number statesNew Journal of Physics, 2006
- Implementing Qubits with Superconducting Integrated CircuitsQuantum Information Processing, 2004
- Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamicsNature, 2004
- Generating and Probing a Two-Photon Fock State with a Single Atom in a CavityPhysical Review Letters, 2002
- Preparing pure photon number states of the radiation fieldNature, 2000
- Generation of Nonclassical Motional States of a Trapped AtomPhysical Review Letters, 1996
- Preparation of Fock states by observation of quantum jumps in an ion trapPhysical Review Letters, 1993