Effects of valley splitting on resonant-tunneling readout of spin qubits

• URL: http://arxiv.org/abs/2501.13289v1
• Date: Thu, 23 Jan 2025 00:26:48 GMT
• Title: Effects of valley splitting on resonant-tunneling readout of spin qubits
• Authors: Tetsufumi Tanamoto, Keiji Ono,
• Abstract summary: The effect of valley splitting on the readout of qubit states is theoretically investigated in a three-quantum-dot (QD) system. A single unit of the three-QD system consists of qubit-QDs and a channel-QD that is connected to a conventional transistor.
• Score: 0.0
• License:
• Abstract: The effect of valley splitting on the readout of qubit states is theoretically investigated in a three-quantum-dot (QD) system. A single unit of the three-QD system consists of qubit-QDs and a channel-QD that is connected to a conventional transistor. The nonlinear source--drain current characteristics under resonant-tunneling effects are used to distinguish different qubit states. Using nonequilibrium Green functions, the current formula for the three-QD system is derived when each QD has two valley energy levels. Two valley states in each QD are considered to be affected by variations in the fabrication process. We found that when valley splitting is smaller than Zeeman splitting, the current nonlinearity can improve the readout, provided that the nonuniformity of the valley energy levels is small. Conversely, when the valley splitting is larger than the Zeeman splitting, the nonuniformity degraded the readout. In both cases, we showed that there are regions where the measurement time $t_{\rm meas}$ is much less than the decoherence time $t_{\rm dec}$ such that $t_{\rm dec}/t_{\rm meas}>100$. This suggests that less than 1\% measurement error is anticipated, which opens up the possibility for implementing surface codes even in the presence of valley splitting.

Related papers

• High-fidelity gates in a transmon using bath engineering for passive leakage reset [65.46249968484794]
  Leakage, the occupation of any state not used in the computation, is one of the most devastating errors in quantum error correction. We demonstrate a device which reduces the lifetimes of the leakage states in the transmon by three orders of magnitude.
  arXiv  Detail & Related papers  (2024-11-06T18:28:49Z)
• Photon Generation in Double Superconducting Cavities: Quantum Circuits Implementation [41.94295877935867]
  We studied photon generation due to the Dynamical Casimir Effect (DCE) in a one dimensional (1+1) double superconducting cavity. The total length of the double cavity $L$, the difference in length between the two cavities $Delta L$, and the electric susceptibility $chi$ are tunable parameters.
  arXiv  Detail & Related papers  (2024-07-19T14:33:45Z)
• Decoherence induced by a sparse bath of two-level fluctuators: peculiar features of $1/f$ noise in high-quality qubits [0.0]
  We show that large variability is a characteristic feature of a qubit dephased by a sparse bath. Our findings help theoretical understanding and further improvements in the coherence properties of semiconductor and superconductor qubits.
  arXiv  Detail & Related papers  (2024-04-29T12:46:32Z)
• Assessing quantum dot SWAP gate fidelity using tensor network methods [0.0]
  The fidelity of SWAP gates is largely unaffected by Zeeman splitting and valley splitting, except when these parameters come into resonance. We analyze the fidelity scaling for long qubit chains without valley effects, where crosstalk represents the only error source.
  arXiv  Detail & Related papers  (2023-07-27T20:11:51Z)
• Photon-induced droplet-like bound states in one-dimensional qubit array [0.0]
  We study the bandgap regime where the energy of two excited qubits is off-resonant with the two-photon bound state band. A two-step adiabatic elimination of the photonic degrees of freedom gives rise to a one-dimensional spin Hamiltonian with effective interactions.
  arXiv  Detail & Related papers  (2023-07-12T01:46:55Z)
• Qubit readouts enabled by qubit cloaking [49.1574468325115]
  Time-dependent drives play a crucial role in quantum computing efforts. They enable single-qubit control, entangling logical operations, as well as qubit readout. Qubit cloaking was introduced in Lled'o, Dassonneville, et al.
  arXiv  Detail & Related papers  (2023-05-01T15:58:25Z)
• Spin-Valley Qubit Dynamics In Exchange Coupled Silicon Quantum Dots [0.0]
  Valley states are a significant obstacle to realizing quantum information technologies in Silicon quantum dots. We use a perturbative analytical approach to study the dynamics of exchange-coupled quantum dots with valley degrees of freedom.
  arXiv  Detail & Related papers  (2021-06-02T18:00:20Z)
• Probing the Spatial Variation of the Inter-Valley Tunnel Coupling in a Silicon Triple Quantum Dot [0.0]
  Electrons confined in silicon quantum dots exhibit orbital, spin, and valley degrees of freedom. The degeneracy can be lifted in silicon quantum wells due to strain and electronic confinement.
  arXiv  Detail & Related papers  (2021-01-29T14:08:50Z)
• Mesoscopic quantum superposition states of weakly-coupled matter-wave solitons [58.720142291102135]
  We establish quantum features of an atomic soliton Josephson junction (SJJ) device. We show that the SJJ-model in quantum domain exhibits unusual features due to its effective nonlinear strength proportional to the square of total particle number. We have shown that the obtained quantum state is more resistant to few particle losses from the condensates if tiny components of entangled Fock states are present.
  arXiv  Detail & Related papers  (2020-11-26T09:26:19Z)
• A multiconfigurational study of the negatively charged nitrogen-vacancy center in diamond [55.58269472099399]
  Deep defects in wide band gap semiconductors have emerged as leading qubit candidates for realizing quantum sensing and information applications. Here we show that unlike single-particle treatments, the multiconfigurational quantum chemistry methods, traditionally reserved for atoms/molecules, accurately describe the many-body characteristics of the electronic states of these defect centers.
  arXiv  Detail & Related papers  (2020-08-24T01:49:54Z)
• Anisotropy-mediated reentrant localization [62.997667081978825]
  We consider a 2d dipolar system, $d=2$, with the generalized dipole-dipole interaction $sim r-a$, and the power $a$ controlled experimentally in trapped-ion or Rydberg-atom systems. We show that the spatially homogeneous tilt $beta$ of the dipoles giving rise to the anisotropic dipole exchange leads to the non-trivial reentrant localization beyond the locator expansion.
  arXiv  Detail & Related papers  (2020-01-31T19:00:01Z)

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.