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Related papers: Dispersive Qubit Readout of Temperature

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We investigate the potential of weak measurement and post-selection to enhance measurement sensitivity when the initial probe state is mixed. In our framework, the mixedness of the probe's density operator is controlled by temperature. We…

Quantum Physics · Physics 2025-09-05 Lorena Ballesteros Ferraz , Alexandre Matzkin , Alok Kumar Pan

The precision of typical thermometers consisting of $N$ particles is shot noise limited, improving as $\sim1/\sqrt{N}$. For high precision thermometry and thermometric standards this presents an important theoretical noise floor. Here it is…

Quantum Physics · Physics 2015-05-19 Thomas M. Stace

Quadrature squeezing of light is investigated in a hybrid atom-optomechanical system comprising a cloud of two-level atoms and a movable mirror mediated by a single-mode cavity field. When the system is at high temperatures with quadrature…

Quantum Physics · Physics 2018-11-14 Yanqiang Guo , Xiaomin Guo , Pu Li , Heng Shen , Jing Zhang , Tiancai Zhang

Recent studies of silicon spin qubits at temperatures above 1 K are encouraging demonstrations that the cooling requirements for solid-state quantum computing can be considerably relaxed. However, qubit readout mechanisms that rely on…

We present a rigorous and quantum-consistent description of dispersive non-Hermitian optical bilayers in the framework of the canonical quantization scheme. Then we investigate the propagation of a normally incident squeezed coherent state…

Quantum Physics · Physics 2022-01-19 Elnaz Pilehvar , Ehsan Amooghorban , Mohammad Kazem Moravvej-Farshi

Single-shot qubit readout typically combines high readout contrast with long-lived readout signals, leading to large signal-to-noise ratios and high readout fidelities. In recent years, it has been demonstrated that both readout contrast…

Quantum Physics · Physics 2017-11-16 Benjamin D'Anjou , William A. Coish

Squeezed light are optical beams with variance below the Shot Noise Level. They are a key resource for quantum technologies based on photons, they can be used to achieve better precision measurements, improve security in quantum key…

Quantum Physics · Physics 2019-04-17 Robert Cernansky , Alberto Politi

Dissipation and decoherence of quantum systems in thermal environments is important to various spectroscopies. It is generally believed that dissipation can broaden the line shape of spectroscopies, and thus stronger system-bath interaction…

Quantum Physics · Physics 2024-05-07 Ru-Qiong Deng , Cheng-Ge Liu , Yi-Xuan Yao , Jing-Yi-Ran Jin , Hao-Yue Zhang , Yin Song , Qing Ai

Squeezing the quadrature noise of a harmonic oscillator used as a sensor can enhance its sensitivity in certain measurment schemes. The canonical approach, based on parametric modulation of the oscillation frequency, is usually limited to a…

Quantum light generated in non-degenerate squeezers has many applications such as sub-shot-noise transmission measurements to maximise the information extracted by one photon or quantum illumination to increase the probability in target…

Quantum Physics · Physics 2020-11-26 Stefan Frick , Alex McMillan , John Rarity

We investigate the prospect of enhancing the phase sensitivity of atom interferometers in the Mach-Zehnder configuration with squeezed light. Ultimately, this enhancement is achieved by transferring the quantum state of squeezed light to…

In quantum reading, a quantum state of light (transmitter) is applied to read classical information. In the presence of noise or for sufficiently weak signals, quantum reading can outperform classical reading by enhanced state…

Quantum Physics · Physics 2015-01-22 Wojciech Roga , Daniela Buono , Fabrizio Illuminati

We report temperature measurements using a transmon qubit by detecting the population of its first three energy levels, after applying a sequence of $\pi$-pulses and performing projective dispersive readout. We measure the effective…

Squeezing of quantum fluctuations by means of entanglement is a well recognized goal in the field of quantum information science and precision measurements. In particular, squeezing the fluctuations via entanglement between two-level atoms…

Quantum Physics · Physics 2009-11-25 J. Appel , P. J. Windpassinger , D. Oblak , U. B. Hoff , N. Kjaergaard , E. S. Polzik

Quantum measurements of mechanical systems can produce optical squeezing via ponderomotive forces. Its observation requires high environmental isolation and efficient detection, typically achieved by using optical cavities and cryogenic…

Fast and high-fidelity qubit measurement is crucial for achieving quantum error correction, a fundamental element in the development of universal quantum computing. For electron spin qubits, fast readout stands out as a major obstacle in…

Mesoscale and Nanoscale Physics · Physics 2024-01-09 Chon-Fai Kam , Xuedong Hu

Squeezed light enables quantum-enhanced phase estimation, with crucial applications in both fundamental physics and emerging technologies. To fully exploit the advantage provided by this approach, estimation protocols must remain optimal…

Quantum Physics · Physics 2025-10-17 Giorgio Minati , Enrico Urbani , Nicolò Spagnolo , Valeria Cimini , Fabio Sciarrino

The performance of a wide range of quantum computing algorithms and protocols depends critically on the fidelity and speed of the employed qubit readout. Examples include gate sequences benefiting from mid-circuit, real-time,…

Fault-tolerant quantum information processing with flawed qubits and gates requires highly efficient, quantum non-demolition (QND) qubit readout. In superconducting circuits, qubit readout using coherent light with fidelity above 99% has…

Quantum Physics · Physics 2024-12-09 G. Liu , X. Cao , T. -C. Chien , C. Zhou , P. Lu , M. Hatridge

We investigate steady-state thermal transport and photon statistics in a nonequilibrium hybrid quantum system, in which a qubit is longitudinally and quadratically coupled to an optical resonator. Our calculations are conducted with the…

Quantum Physics · Physics 2021-09-08 Chen Wang , Hua Chen , Jie-Qiao Liao