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Related papers: Thermometry Based on a Superconducting Qubit

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Temperature estimation, known as thermometry, is a critical sensing task for physical systems operating in the quantum regime. Indeed, thermal fluctuations can significantly degrade quantum coherence. Therefore, accurately determining the…

We experimentally demonstrate the fast generation of thermal states of a transmon using a single-junction quantum-circuit refrigerator (QCR) as an in-situ-tunable environment. Through single-shot readout, we monitor the transmon up to its…

A number of superconducting qubits, such as the transmon or the phase qubit, have an energy level structure with small anharmonicity. This allows for convenient access of higher excited states with similar frequencies. However, special care…

Quantum Physics · Physics 2011-02-14 R. Bianchetti , S. Filipp , M. Baur , J. M. Fink , C. Lang , L. Steffen , M. Boissonneault , A. Blais , A. Wallraff

We address the dephasing dynamics of the quantum Fisher information (QFI) for the process of quantum thermometry with probes coupled to squeezed thermal baths via the nondemolition interaction. We also calculate the upper bound for the…

Quantum Physics · Physics 2020-03-05 H. Rangani Jahromi

A theoretical proposal that Coulomb-coupled quantum dots can be used as quantum probes to determine the temperature of a sample (i.e., an electronic reservoir) is proposed. Through the regulation of the positive or negative voltage bias in…

Mesoscale and Nanoscale Physics · Physics 2019-08-13 Yanchao Zhang , Jincan Chen

On-chip thermometry at deep-cryogenic temperatures is vital in quantum computing applications to accurately quantify the effect of increased temperature on qubit performance. In this work, we present a sub-1 K temperature sensor in CMOS…

The quantum bits (qubits) on which superconducting quantum computers are based have energy scales corresponding to photons with GHz frequencies. The energy of photons in the gigahertz domain is too low to allow transmission through the…

Temperature is a deceptively simple concept that still raises deep questions at the forefront of quantum physics research. The observation of thermalisation in completely isolated quantum systems, such as cold-atom quantum simulators,…

Quantum Physics · Physics 2022-03-09 Mark T. Mitchison , Archak Purkayastha , Marlon Brenes , Alessandro Silva , John Goold

Measuring thermodynamic quantities can be easy or not, depending on the system that is being studied. For a macroscopic object, measuring temperatures can be as simple as measuring how much a column of mercury rises when in contact with the…

Quantum Physics · Physics 2015-09-15 O. P. de Sá Neto , M. C. de Oliveira , G. J. Milburn

We characterize a superconducting qubit before and after embedding it along with its package in an absorptive medium. We observe a drastic improvement in the effective qubit temperature and over a tenfold improvement in the relaxation time…

We demonstrate a new method to directly manipulate the state of individual two-level systems (TLS) in phase qubits. It allows one to characterize the coherence properties of TLS using standard microwave pulse sequences, while the qubit is…

Superconductivity · Physics 2010-12-09 J. Lisenfeld , C. Müller , J. H. Cole , P. Bushev , A. Lukashenko , A. Shnirman , A. V. Ustinov

Ongoing experimental activity aims at calorimetric measurements of thermodynamic indicators of quantum integrated systems. We study a model of a driven qubit in contact with a finite-size thermal electron reservoir. The temperature of the…

Quantum Physics · Physics 2019-05-08 Brecht Donvil , Paolo Muratore-Ginanneschi , Jukka P. Pekola

This paper demonstrates the use of voltage noise thermometry, with a cross-correlation technique, as a dissipation-free method of thermometry inside a CMOS integrated circuit (IC). We show that this technique exhibits broad agreement with…

In this work, we study the thermodynamics of a two-level system (qubit) embedded in a finite-temperature structured-bath under periodical measurements. The system under measurements will reach a quasi-steady state, whose effective…

Quantum Physics · Physics 2019-08-14 Jia-Ming Zhang , Jun Jing , Lian-Ao Wu , Li-Gang Wang , Shi-Yao Zhu

Motivated by the recent development of fast and ultra-sensitive thermometry in nanoscale systems, we investigate quantum calorimetric detection of individual heat pulses in the sub-meV energy range. We propose a hybrid superconducting…

Mesoscale and Nanoscale Physics · Physics 2018-11-28 F. Brange , P. Samuelsson , B. Karimi , J. P. Pekola

Quantifying the temperature of microdevices is critical for probing nanoscale energy transport.Such quantification is often accomplished by integrating resistance thermometers into microdevices. However, such thermometers frequently become…

Mesoscale and Nanoscale Physics · Physics 2021-05-05 Amin Reihani , Shen Yan , Yuxuan Luan , Rohith Mittapally , Edgar Meyhofer , Pramod Reddy

We present measurements of coherence and successive decay dynamics of higher energy levels of a superconducting transmon qubit. By applying consecutive $\pi$-pulses for each sequential transition frequency, we excite the qubit from the…

A large fraction of quantum science and technology requires low-temperature environments such as those afforded by dilution refrigerators. In these cryogenic environments, accurate thermometry can be difficult to implement, expensive, and…

Applied Physics · Physics 2020-07-07 C. A. Potts , V. A. S. V. Bittencourt , S. Viola Kusminskiy , J. P. Davis

Measuring the state of qubits is one of the fundamental operations of a quantum computer. Currently, state-of-the-art high-fidelity single-shot readout of superconducting qubits relies on parametric amplifiers at the millikelvin stage.…

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…