Exponentially-enhanced quantum sensing with many-body phase transitions

Understand

Quantum sensors based on critical many-body systems are known to exhibit enhanced sensing capability.

• Such enhancements typically scale algebraically with the probe size.
• Going beyond algebraic advantage and reaching exponential scaling has remained elusive when all the resources, such as the preparation time, are taken into account.
• In this work, we show that many-body systems featuring first order quantum phase transitions can indeed achieve exponential scaling of sensitivity, thanks to their exponential energy gap closing.