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Spin-motion coupling in atoms. Cooling to motional ground states and Quantum logic spectroscopy. Ingredients. k. k. k. Rotating frame. Rotating wave approximation. k. k. k. k. Another r otating frame. Another r otating frame. Carrier interaction.
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Spin-motion coupling in atoms Cooling to motional ground states and Quantum logic spectroscopy
k Rotating frame Rotating wave approximation
Another rotating frame Carrier interaction
Another rotating frame Red sideband interaction Interaction strength given by
Another rotating frame Blue sideband interaction Interaction strength given by
Resolved sideband cooling Step 1: Doppler cool Ion cooled to ground state: PRL 75, 4011 (1995) Neutral atom cooled to ground state: PRX 2, 041014(2012)
Resolved sideband cooling Step 1: Doppler cool g/2p = 20 MHz F=1 2P1/2 Step 2: Pump to F=0 370 nm F=1 | 2S1/2 | F=0 Ion cooled to ground state: PRL 75, 4011 (1995) Neutral atom cooled to ground state: PRX 2, 041014(2012)
Resolved sideband cooling Step 1: Doppler cool g/2p = 20 MHz F=1 2P1/2 Step 2: Pump to F=0 Step 3: Apply red sideband Ion cooled to ground state: PRL 75, 4011 (1995) Neutral atom cooled to ground state: PRX 2, 041014(2012)
Resolved sideband cooling Step 1: Doppler cool g/2p = 20 MHz F=1 2P1/2 Step 2: Pump to F=0 Step 3: Apply red sideband Step 4: Pump to Ion cooled to ground state: PRL 75, 4011 (1995) Neutral atom cooled to ground state: PRX 2, 041014(2012)
Resolved sideband cooling Step 1: Doppler cool g/2p = 20 MHz F=1 2P1/2 Step 2: Pump to F=0 Step 3: Apply red sideband Step 4: Pump to etc Finish in … How to check? Ion cooled to ground state: PRL 75, 4011 (1995) Neutral atom cooled to ground state: PRX 2, 041014(2012)
Measuring phonon number and spin state Assume thermal state with mean phonon number Red sideband interaction strength given by Blue sideband interaction strength given by Probe red, blue sidebands for same duration Ion cooled to ground state: PRL 75, 4011 (1995) Neutral atom cooled to ground state: PRX 2, 041014(2012)
Measuring phonon number and spin state Assume thermal state with mean phonon number Before: asymmetry 1/3 After: asymmetry 1/67 Ion cooled to ground state: PRL 75, 4011 (1995) Neutral atom cooled to ground state: PRX 2, 041014(2012)
Quantum logic spectroscopy Motivation: Probe a “clock” transition when you don’t have a cycling transition Spectroscopy ion Logic ion Science 309, 749 (2005)
Quantum logic spectroscopy Motivation: Probe a “clock” transition when you don’t have a cycling transition Spectroscopy ion Logic ion Science 309, 749 (2005)
Quantum logic spectroscopy Al+ Be+ Step 1: Initialization n=1 n=0 n=1 n=0 Science 309, 749 (2005)
Quantum logic spectroscopy Al+ Be+ Step 1: Initialization n=1 n=0 Step 2: Interrogate clock transition n=1 n=0 Science 309, 749 (2005)
Quantum logic spectroscopy Al+ Be+ Step 1: Initialization n=1 n=0 Step 2: Interrogate clock transition n=1 n=0 Step 3: Drive red sideband on Al Science 309, 749 (2005)
Quantum logic spectroscopy Al+ Be+ Step 1: Initialization n=1 n=0 Step 2: Interrogate clock transition n=1 n=0 Step 3: Drive red sideband on Al Step 4: Drive red sideband on Be Step 5: Read out Be Science 309, 749 (2005)
Quantum logic spectroscopy Al+ Be+ n=1 n=0 n=1 n=0 Science 309, 749 (2005)
Quantum logic spectroscopy: Initialization sequence Al+ - Carrier transition with mF = 5/2 mF = 3/2 mF= 1/2 … n=1 n=0 mF = 1/2 mF = 3/2 mF =5/2
Quantum logic spectroscopy: Initialization sequence Al+ - Carrier transition with mF = 5/2 mF = 3/2 - Red sideband transition with mF= 1/2 … n=1 n=0 mF = 1/2 mF = 3/2 mF =5/2
Quantum logic spectroscopy: Initialization sequence Al+ - Carrier transition with mF = 5/2 mF = 3/2 - Red sideband transition with mF= 1/2 - Laser cool the motional mode (with Be) … n=1 n=0 mF = 1/2 mF = 3/2 mF =5/2
Quantum logic spectroscopy: Initialization sequence Al+ - Carrier transition with mF = 5/2 mF = 3/2 - Red sideband transition with mF= 1/2 - Laser cool the motional mode (with Be) … n=1 n=0 mF = 1/2 mF = 3/2 mF =5/2
Other uses for spin-motion coupling • Cooling oscillators to their ground state • Trapped ions, neutral atoms • Mesoscopic oscillators • Making ions talk to each other • Entanglement • Spectroscopy for atomic clocks • Quantum simulations • Magnetism in ions • Synthetic gauge fields in neutral atoms