A Hybrid Measurement Scheme for Generating nonGaussian Spin States

• URL: http://arxiv.org/abs/2502.19527v2
• Date: Mon, 31 Mar 2025 19:17:37 GMT
• Title: A Hybrid Measurement Scheme for Generating nonGaussian Spin States
• Authors: Andrew Kolmer Forbes, Ivan H. Deutsch,
• Abstract summary: We present a protocol for generating nonclassical states of atomic spin ensembles.<n>We create a spin squeezed state by measuring the light's polarization rotation.<n>We detect single photons scattered into the signal mode.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We present a protocol for generating nonclassical states of atomic spin ensembles through the backaction induced by a hybrid measurement of light that is entangled with atoms, combining both homodyne and single photon detection. In phase-I of the protocol we create a spin squeezed state by measuring the light's polarization rotation due to the Faraday effect in a balanced polarimeter, equivalent to a homodyne measurement. In phase-II we send a second probe beam through the sample and detect single photons scattered into the signal mode. Before doing so, we rotate the uncertainty bubble to increase the projection fluctuations of the measured spin component. This increases the coupling strength between the atoms and photons and thus the rate of scattering of single photons into the signal mode. In the ideal case, the result is a squeezed Dicke state, with substantial quantum advantage for sensing spin rotations. We benchmark the protocol's utility in the presence of inevitable decoherence due to optical pumping using the Fisher information as a measure of quantum advantage. We show that in the presence of decoherence, the quantum Fisher information associated with the nonGaussian mixed state we prepare is substantially larger than the classical Fisher information obtained from the standard measurement of spin rotations. We deduce a measurement basis that is close to optimal for achieving the quantum Cram\'{e}r Rao bound in the presence of decoherence.

Related papers

• Measurement-induced back-action and spin-to-polarization mapping in a quantum dot-based receiver [0.0]
  Polarization-encoded spin-photon interfaces constitute promising candidates for the development of stationary nodes used as photon receivers. We introduce a time-resolved tomography approach which allows observing the dynamics of an electron spin in a semiconductor quantum dot.
  arXiv  Detail & Related papers  (2025-03-30T21:15:11Z)
• Broadband biphoton source for quantum optical coherence tomography based on a Michelson interferometer [39.58317527488534]
  We describe and experimentally demonstrate a novel technique for generation of a bright collinear biphoton field with a broad spectrum.<n>As the most straightforward application of the source, we employ Michelson interferometer-based quantum optical coherence tomography (Q OCT)
  arXiv  Detail & Related papers  (2024-01-31T13:52:37Z)
• Low-noise Balanced Homodyne Detection with Superconducting Nanowire Single-Photon Detectors [0.0]
  Superconducting nanowire single-photon detectors (SNSPDs) have been widely used to study the discrete nature of quantum states of light. We show that SNSPDs can also be used to study continuous variables of optical quantum states by performing homodyne detection at a bandwidth of $400mathrmkHz$.
  arXiv  Detail & Related papers  (2023-07-31T13:47:45Z)
• Detecting spin bath polarization with quantum quench phase shifts of single spins in diamond [9.257887191970825]
  Single-qubit sensing protocols can be used to measure qubit-bath coupling parameters. For sufficiently large coupling, the sensing protocol itself perturbs the bath, which is predicted to result in a characteristic response in the sensing measurements. Here, we observe this bath perturbation, also known as a quantum quench, by preparing the nuclear spin bath of a nitrogen-vacancy (NV) center in polarized initial states.
  arXiv  Detail & Related papers  (2023-03-03T21:54:35Z)
• Controlling photon polarisation with a single quantum dot spin [0.0]
  We demonstrate the control of giant polarisation rotations induced by a single electron spin. We find that the polarisation state of the reflected photons can be manipulated in most of the Poincar'e sphere, through controlled spin-induced rotations. This control allows the operation of spin-photon interfaces in various configurations, including at zero or low magnetic fields.
  arXiv  Detail & Related papers  (2022-12-07T16:37:59Z)
• Entanglement of annihilation photons [141.5628276096321]
  We present the results of a new experimental study of the quantum entanglement of photon pairs produced in positron-electron annihilation at rest. Despite numerous measurements, there is still no experimental proof of the entanglement of photons.
  arXiv  Detail & Related papers  (2022-10-14T08:21:55Z)
• Quantifying n-photon indistinguishability with a cyclic integrated interferometer [40.24757332810004]
  We report on a universal method to measure the genuine indistinguishability of n-photons. Our approach relies on a low-depth cyclic multiport interferometer with N = 2n modes. We experimentally demonstrate this technique for a 8-mode integrated interferometer fabricated using femtosecond laser micromachining.
  arXiv  Detail & Related papers  (2022-01-31T16:30:52Z)
• A quantum ring gyroscope based on coherence de Broglie waves [0.0]
  In a Mach-Zenhder interferometer (MZI), the highest precision for a measurement error is given by vacuum fluctuations of quantum mechanics. We propose another method for the high precision measurement overcoming the Heisenberg photon-phase relation. For a potential application of the proposed method, a quantum ring gyroscope is presented.
  arXiv  Detail & Related papers  (2021-11-05T02:23:47Z)
• Visualizing spinon Fermi surfaces with time-dependent spectroscopy [62.997667081978825]
  We propose applying time-dependent photo-emission spectroscopy, an established tool in solid state systems, in cold atom quantum simulators. We show in exact diagonalization simulations of the one-dimensional $t-J$ model that the spinons start to populate previously unoccupied states in an effective band structure. The dependence of the spectral function on the time after the pump pulse reveals collective interactions among spinons.
  arXiv  Detail & Related papers  (2021-05-27T18:00:02Z)
• Quantum Borrmann effect for dissipation-immune photon-photon correlations [137.6408511310322]
  We study theoretically the second-order correlation function $g(2)(t)$ for photons transmitted through a periodic Bragg-spaced array of superconducting qubits, coupled to a waveguide. We demonstrate that photon bunching and anti-bunching persist much longer than both radiative and non-radiative lifetimes of a single qubit.
  arXiv  Detail & Related papers  (2020-09-29T14:37:04Z)
• Quantum Zeno effect under continuous spin noise measurement in a quantum dot-micropillar cavity [0.0]
  We describe the quantum Zeno effect in a spin-photon interface represented by a charged quantum dot in a micropillar cavity. We obtain a microscopic expression for the spin measurement rate and calculate the second and fourth order correlation functions of the spin noise. We demonstrate, that the quantum limit for the spin measurement can be reached for any probe frequency using the homodyne nondemolition spin measurement.
  arXiv  Detail & Related papers  (2020-08-14T16:07:05Z)
• Entanglement robustness to excitonic spin precession in a quantum dot [43.55994393060723]
  A semiconductor quantum dot (QD) is an attractive resource to generate polarization-entangled photon pairs. We study the excitonic spin precession (flip-flop) in a family of QDs with different excitonic fine-structure splitting (FSS) Our results reveal that coherent processes leave the time post-selected entanglement of QDs unaffected while changing the eigenstates of the system.
  arXiv  Detail & Related papers  (2020-01-31T13:50:51Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.