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Hitoshi Inamori

Publications and source records attributed to Hitoshi Inamori.

12 recordsLinked to original sources
arXiv2021

An alternative to test experimentally Everett's theory

It is generally accepted that Everett's theory of quantum mechanics cannot be experimentally tested as such experiment would involve operations on the observer which are beyond our current technology. We propose an alternative to test Everett's theory which does not involve any operation on the observer. If we assume that the observer is of finite dimension, it is shown that Everett's theory leads to distinctive properties for the system being observed, and that such difference can be experimentally tested.

quant-ph↗
arXiv2018

The issue with the initial state in quantum mechanics

In the conventional formulation of quantum mechanics, the initial description is given only for the physical system under study. It factors out the state for the experimenter. We argue that such description is incomplete and can lead to statements which can in theory be meaningless. We propose that within a complete description, the initial state must include the state of the experimenter. With such formulation quantum mechanics provides joint probabilities for conjointly observed events, rather than a probability conditional on some initial state for the system under study. This feature is desirable, as with quantum mechanics, statements on what happened in the past may have no meaning in the present.

quant-ph↗
arXiv2018

Quantum mechanics allows undetectable inconsistencies in witnessed events

Quantum mechanics, devoid of any additional assumption, does not give any theoretical constraint on the projection basis to be used for the measurement process. It is shown in this paper that it does neither allow any physical means for an experimenter to determine which measurement bases have been used by another experimenter. As a consequence, quantum mechanics allows a situation in which two experimenters witness incoherent stories without being able to detect such incoherence, even if they are allowed to communicate freely by exchanging iterative and bilateral messages.

physics.gen-ph↗
arXiv2017

The general invariance of physical laws

Physical laws are a set of rules in the relationship between observations made by the experimenter. All these observations are made through a mechanism that links the external world to the experimenter's awareness, a mechanism which is not under the experimenter's control. We discuss how this mechanism can affect the physical laws as implied by the experimenter, and define fundamental physical laws as the ones which remain invariant under the change of such mechanism.

quant-ph↗
arXiv2016

Is independent choice possible?

This paper questions the generally accepted assumption that one can make a random choice that is independent of the rest of the universe. We give a general description of any setup that could be conceived to generate random numbers. Based on the fact that the initial state of such setup together with its environment cannot be known, we show that the independence of its generated output cannot be guaranteed. Some consequences of this theoretical limitation are discussed.

quant-ph↗
arXiv2016

No Quantum Process Can Explain the Existence of the Preferred Basis: Decoherence Is Not Universal

Environment induced decoherence, and other quantum processes, have been proposed in the literature to explain the apparent spontaneous selection - out of the many mathematically eligible bases - of a privileged measurement basis that corresponds to what we actually observe. This paper describes such processes, and demonstrates that - contrary to common belief - no such process can actually lead to a preferred basis in general. The key observation is that environment induced decoherence implicitly assumes a prior independence of the observed system, the observer and the environment. However, such independence cannot be guaranteed, and we show that environment induced decoherence does not succeed in establishing a preferred measurement basis in general. We conclude that the existence of the preferred basis must be postulated in quantum mechanics, and that changing the basis for a measurement is, and must be, described as an actual physical process.

physics.gen-ph↗
arXiv2015

Defining the Observed World in Quantum Mechanics

This paper defines what constitutes the Observed World in the Quantum Mechanical framework, based strictly on what is actually observed beyond doubt, instead of building observables on what is inferred from actual observations. Such principle narrows down considerably what can be considered as being part of the Observed World. On the other hand, we argue that some information - that is in general assumed as granted - should actually be considered as being part of the Observed World. We discuss the implications of such assertion, in the way we perceive time evolution, information growth and causality.

quant-ph↗
arXiv2001

Unconditional Security of Practical Quantum Key Distribution

We present a complete protocol for BB84 quantum key distribution for a realistic setting (noise, loss, multi-photon signals of the source) that covers many of todays experimental implementations. The security of this protocol is shown against an eavesdropper having unrestricted power to manipulate the signals coherently on their path from sender to receiver. The protocol and the security proof take into account the effects concerning the finite size of the generated key.

quant-ph↗
arXiv2000

Basic concepts in quantum computation

Section headings: 1 Qubits, gates and networks 2 Quantum arithmetic and function evaluations 3 Algorithms and their complexity 4 From interferometers to computers 5 The first quantum algorithms 6 Quantum search 7 Optimal phase estimation 8 Periodicity and quantum factoring 9 Cryptography 10 Conditional quantum dynamics 11 Decoherence and recoherence 12 Concluding remarks

quant-ph↗
arXiv2000

Security of EPR-based Quantum Key Distribution using three bases

Modifications to a previous proof of the security of EPR-based quantum key distribution are proposed. This modified version applies to a protocol using three conjugate measurement bases rather than two. A higher tolerable error rate is obtained for the three-basis protocol.

quant-ph↗
arXiv2000

Security of EPR-based Quantum Key Distribution

We propose a proof of the security of EPR-based quantum key distribution against enemies with unlimited computational power. The proof holds for a protocol using interactive error-reconciliation scheme. We assume in this paper that the legitimate parties receive a given number of single photon signals and that their measurement devices are perfect.

quant-ph↗